The UK Government has been urged to “take violence against women seriously” after failing to ratify a major international treaty on domestic violence four years after it pledged to do so.

In an open letter published by The Independent, UN Women’s Goodwill Ambassador Emma Watson, campaigners, human rights lawyers and senior political figures including Labour leader Jeremy Corbyn and Liberal Democrat leader Tim Farron have called on Theresa May to take the opportunity to “recognise that women’s rights are human rights” by ratifying the Istanbul Convention.

The letter is being published in advance of a major vote tomorrow in Parliament when MPs will have the opportunity to back a private members bill to enshrine a leading international treaty on domestic violence in British law. The bill is at its second reading, meaning MPs will vote on whether it should pass on to the next step of being considered by a committee.

It is likely to pass in the parliamentary vote tomorrow, as Labour, the SNP, the Green Party and the Lib Dems all support it. However, for it to pass into law it would need the support of the Conservative Party as the largest party.

The call to ratify the convention comes after a four-year period has elapsed in which the Government has failed to ratify domestic violence provisions, despite pledging to do so in 2012.

Human rights lawyer Lisa Gormley has said the convention will act as a “catalyst for real change” that will force the UK Government to take comprehensive action to improve the lives of those who are victims of rape, stalking and harassment.

The Istanbul convention has been described as the “gold standard” of legislation on gender-based violence and addresses FGM, domestic violence, sexual abuse and child marriage.

Countries that incorporate the treaty commit to ensuring survivors of domestic violence can have access to specialist support services and refuges, monitoring data about gender-based violence and having age appropriate education at schools about domestic abuse.

Although many forms of domestic and sexual abuse are already illegal in the UK, some of the legislation commits to general principles of victims’ “welfare and wellbeing” which can be subject to interpretation by different courts and local councils, resulting in varying access to welfare and other provisions.

The convention has already been signed by 22 countries including Italy, France, the Netherlands, Sweden, Finland and Spain.

Emma Watson's new short film highlights hurdles in fight for women's equality

The Government agreed to sign the convention in 2012 but the refusal to commit further through full ratification has incensed campaigners.

The Government has defended the delay saying in 2015 that it remains committed: “We have already cemented our standing as a world leader in this important area, hosting major international summits to tackle female genital mutilation and forced marriage. We already comply with the vast majority of the Convention’s articles.”

However, some critics cited concerns the delay was due to a further implication that some aspects of austerity and local government cuts could become illegal under the convention – the bedroom tax, for example, could impact on properties specially adapted for domestic violence victims with panic rooms and alarms.

Dubravka Šimonović, the UN’s special rapporteur on violence against women, is a leading ambassadorial voice on gender-based violence internationally. She has also signed the letter calling for ratification, telling The Independent: “If the Government is committed to preventing and eliminating violence against women and girls it should ratify this convention now and start working on its incorporation and implementation. The Istanbul Convention will provide a new impetus at the political, legal and social level to focus on combatting and preventing violence against women and to incorporate additional provisions of services that are usually inadequate, such as helplines and shelters.”

UK news in pictures Show all 50 1 /50 UK news in pictures UK news in pictures 18 September 2020 A model presents a creation during the Bora Aksu catwalk show at London Fashion Week 2020 Reuters UK news in pictures 17 September 2020 World kickboxing champion Carl Thomas during his attempt to run a marathon while pulling a plane at Elvington Airfield near York. The attempt is raising funds for Ollie's Army Battling Against Battens, an organisation campaigning to raise GBP 250,000 to fund a clinical trial aimed at saving the sight of children with CNL2 Batten Disease PA UK news in pictures 16 September 2020 Labour deputy leader Angela Rayner speaking during Prime Minister's Questions UK Parliament/AFP/Getty UK news in pictures 15 September 2020 People enjoying the autumn sunshine as they punt along the River Cam in Cambridge PA UK news in pictures 14 September 2020 Early morning light bathes the skyscrapers of the City of London, at the start of a week in which the UK is expected to bask in temperatures of more than 30 degrees PA UK news in pictures 13 September 2020 England celebrate after they dismissed Australia's Alex Carey to win the second ODI match of the series at Emirates Old Trafford, Manchester PA UK news in pictures 12 September 2020 Protesters outside BBC Broadcasting House in central London, as marches and rallies form across the country calling for a 15% pay rise for NHS workers and an increase in NHS funding PA UK news in pictures 11 September 2020 An empty migrant dinghy floats off the beach at St Margaret's Bay after the occupants landed from France in Dover Getty UK news in pictures 10 September 2020 A view of small boats thought to be used in migrant crossings across the Channel at a storage facility in Dover, Kent PA UK news in pictures 9 September 2020 EU's chief negotiator Michel Barnier, left, arriving from the Eurostar with EU Ambassador to the UK, Portuguese diplomat Joao Vale de Almeida at St Pancras International railway station, London, for the latest round of the negotiations on a free trade deal between the EU and the UK PA UK news in pictures 8 September 2020 Dawn over Coquet Island, a small island off Amble on the Northumberland coast PA UK news in pictures 7 September 2020 A hovercraft arrives to Southsea, Hampshire from the Isle of Wight PA UK news in pictures 6 September 2020 Forensics officers near the scene of multiple reported stabbings in Birmingham Reuters UK news in pictures 5 September 2020 Anti-migrant protesters demonstrate in Dover against immigration and the journeys made by refugees crossing the Channel to Kent PA UK news in pictures 4 September 2020 Activists take part in a demonstration against the HS2 hi-speed rail line outside the Department of Transport AFP via Getty UK news in pictures 3 September 2020 Peter Baker, who plays Trigger in the musical version of Only Fools and Horses, sweeps the stage of the Theatre Royal Haymarket in London, after observing a 15 minute silence to show solidarity with those in the theatre industry that have lost their jobs due to the coronavirus pandemic PA UK news in pictures 2 September 2020 Kadie Lane, right, 11, and Brooke Howourth, 11, hug on their walk to Marden Bridge Middle School in Whitley Bay, Tyne and Wear, for their first day of term, as schools in England reopen to pupils following the coronavirus lockdown PA UK news in pictures 1 September 2020 Extinction Rebellion protesters sitting outside The Houses of Parliament in Westminster, London PA UK news in pictures 31 August Surfers at Long Sands Beach, Tynemouth PA UK news in pictures 30 August Black Lives Matter protesters march through Notting Hill in London in the first Million People March EPA UK news in pictures 29 August A protester reacts as she demonstrates against the lockdown and use of face masks, amid the coronavirus disease outbreak, outside Downing Street in London Reuters UK news in pictures 28 August Caribbean soca dancers display their costumes as they promote the first ever digital Notting Hill Carnival, following the cancellation of the normal Carnival festivities due to the continued spread of the coronavirus disease, in London Reuters UK news in pictures 27 August Father and son team Chris and Sam Milford from historic building conservation specialists WallWalkers begin restoration work on the spire of Norwich Cathedral, which stands at over 312ft high. The first known spire was completed in 1297 PA UK news in pictures 26 August Giant waves at Seaham in County Durham, as the bad weather continues PA UK news in pictures 25 August An assistant at the Wallace Monument cleans the case which houses the William Wallace sword in the Hall of Arms room at the monument near Stirling as they prepare to re-open PA UK news in pictures 24 August Restored World War Two landing craft LCT 7074 is transported from from the Naval Base in Portsmouth to its final resting place at the D-Day Story at Southsea PA UK news in pictures 23 August Jenny Nguyen and Tony Cao, from Vietnam, pose for wedding photos on Tower Bridge in London, as it remains closed to vehicles after it was stuck open on Saturday due to a "mechanical fault". The landmark's Twitter account confirmed only pedestrians and cyclists could use it on Sunday morning PA UK news in pictures 22 August England's Zak Crawley hit 267, joining the exclusive Double Hundred club, on day two of the Third Test match against Pakistan at the Ageas Bowl, Southampton PA UK news in pictures 21 August Harri Teale gathers lavender during the annual harvest on the Wolds Way Lavender farm near Malton in North Yorkshire PA UK news in pictures 20 August Parents and a student react after checking GCSE results at Ark Academy in London Reuters UK news in pictures 19 August Tate Modern workers hold a strike outside the gallery in London, to protest the institution's announcement that it would cut more than 300 jobs from its commercial arm, Tate Enterprises PA UK news in pictures 18 August Two rescued brown bear cubs, Mish (left) and Lucy, cool off in a pool after arriving at their new home with the wildlife conservation charity Wildwood Trust in Herne Bay, Kent. The orphaned pair, who have been living in a temporary home in Belgium since they were found abandoned and alone in a snowdrift in the Albanian mountains, will be acclimatised to their new life in the country before moving to a permanent home PA UK news in pictures 17 August A level students celebrate outside the Department for Education in London after it was confirmed that candidates in England will be given grades estimated by their teachers, rather than by an algorithm. The government U-turn comes just days after Education Secretary Gavin Williamson vowed there would be "no U-turn, no change. PA UK news in pictures 16 August Wasp players take a knee as Northampton Saints stand prior to kick-off in their Premiership match at Franklin's Gardens PA UK news in pictures 15 August Piper Colour Sergeant Lil Bahadur Gurung attends the VJ Day National Remembrance event, held at the National Memorial Arboretum in Staffordshire, Britain Reuters UK news in pictures 14 August People including students hold placards on Whitehall outside Downing Street as they protest against the downgrading of A-level results. The government faced criticism after education officials downgraded more than a third of pupils' final grades in a system devised after the coronavirus pandemic led to cancelled exams yes AFP via Getty UK news in pictures 13 August Benita Stipp (centre) and Mimi Ferguson (left) react as students at Norwich School receive their A-Level results PA UK news in pictures 12 August 2020 A train derailment near Stonehaven has left three people dead. Driver Brett McCullough, conductor Donald Dinnie, and a passenger were killed when the 6.38am Aberdeen to Glasgow Queen Street service crashed amid heavy rain and flooding BBC UK news in pictures 11 August 2020 A woman hydrates in the sun after open water swimming at the West Reservoir Centre in north London Tolga Akmen/AFP via Getty UK news in pictures 10 August 2020 Prime Minister Boris Johnson takes part in an archery session as he visits Premier Education Summer Camp at Sacred Heart of Mary Girls' in Upminster Reuters UK news in pictures 9 August 2020 People cycle through Cambridge as the heatwave continues in Britain EPA UK news in pictures 8 August 2020 Healthcare workers take part in a protest in London over pay conditions in the NHS Getty UK news in pictures 7 August 2020 Emergency services make their way along the seafront on Bournemouth beach in Dorset on one of the hottest days of the year PA UK news in pictures 6 August 2020 Alison Murphy poses for a picture by husband Peter as she walks through a field of sunflowers in Altrincham, Cheshire PA UK news in pictures 5 August 2020 Pakistan's Abid Ali being bowled by England's Jofra Archer during day one of the First Test match at the Emirates Old Trafford, Manchester PA UK news in pictures 4 August 2020 The 'Timbuktu tumblers' from Kenya perform their balancing act on the Southsea waterfront as Zippos Circus reopens in Portsmouth Rex UK news in pictures 3 August 2020 Pelicans interact with a visitor in St James's Park in London PA UK news in pictures 2 August 2020 Lewis Hamilton drives with a puncture towards the finish line to win the Formula One British Grand Prix at Silverstone POOL/AFP via Getty UK news in pictures 1 August 2020 Arsenal's Pierre-Emerick Aubameyang celebrates with the trophy and teammates after winning the FA Cup, as play resumes behind closed doors following the outbreak of the coronavirus disease Pool via Reuters UK news in pictures 31 July 2020 People enjoy the sunny weather at a Bournemouth Beach Reuters

Human rights lawyers backed the calls. Lisa Gormley, from the Centre for Women, Peace and Security at the London School of Economics, told The Independent: “The Istanbul Convention is a catalyst for real change - using best practice know-how. It is different from previous domestic violence laws because it is a comprehensive integrated plan across all forms of violence against women. This is important because some forms of violence affect the same women and girls in multiple ways – there needs to be a comprehensive approach.”

Actress Emma Watson, the UN Women’s Goodwill Ambassador, is also among signatories to the letter. An ambassador for the human rights body since 2014, she has campaigned for women and girls rights both in the UK and internationally.

SNP MP Dr Eilidh Whiteford, who is introducing the private members bill on which MPs will vote tomorrow, says it is imperative the convention is ratified because it will provide the legal apparatus to hold governments accountable for their progress.

“It is important that the Istanbul Convention is ratified because it is the most comprehensive framework that exists anywhere to tackle violence against women in its many forms and manifestations.

“Here in the UK some good progress has been made to address serious issues like forced marriage, stalking and so-called revenge porn, but thanks to the Government’s austerity agenda – vital local services such as women’s refuges and rape crisis helplines are at risk. Ratifying the Istanbul Convention will secure in law women’s right to access these services. Tomorrow we have a real opportunity to make a difference to the lives of women here and abroad.”

Gender-based violence can include female genital mutilation, forced marriage, as well as domestic or sexual abuse. It can involve physical, emotional or sexual violence or harm. It primarily affects women and girls but can also affect men, boys and non-binary people. On average, two women are killed by their current or former partner in England and Wales every week.

It is estimated that 7.7 per cent of all women and 4.4 per cent of all men suffer from domestic violence at some point in their lives.

A Government spokesperson told The Independent: “We remain committed to ratifying the Istanbul Convention as part of our strong commitment to tackling violence against women and girls. In most respects measures already in place to protect women and girls from violence comply with, or go further, than the Convention requires.”

Full text: Letter to the British Government on the eve of the Private Member’s Bill on the Istanbul Convention

“We are faced with a unique opportunity to #ChangeHerstory and help end gender-based violence in the UK.

The Istanbul Convention is a historic international treaty which makes governments legally bound to prevent gender-based violence. It recognises that women’s rights are human rights and commits governments to take violence against women seriously.

The UK Government signed the Convention in 2012, yet in the four years since it has failed to ratify it. Until it is ratified, the convention remains just a piece of paper and fails to protect women and girls.

Every hour of every day, the police receive over 100 calls about domestic abuse. On average, two women are killed by their current or former partner every week in England and Wales. Women and girls in the UK need their Government to take this issue seriously and act now.

Ratifying the convention would mean:

- Survivors of domestic violence are entitled to specialist services and support such as refuges and shelters

- Survivors of abuse are entitled to psychological support

- 24 hour helplines are available for all forms of violence against women

- Robust data monitoring gender-based violence is collected

- Education is given in schools on issues such as gender equality and violence against women and girls

Gender-based violence can take many forms including FGM, so-called Honour Based Violence, child marriage, domestic abuse and sexual abuse, which are recognised by the Istanbul Convention. It primarily affects women but can also affect men and non-binary people.

On Friday 16 December, the Government has a unique opportunity to show its commitment to preventing gender-based violence. MPs can lend their power to ratification of the Istanbul Convention by supporting the second reading of the Preventing and Combating Violence Against Women and Domestic Violence Bill as it goes before parliament.

This Bill has cross-party support, and is backed by organisations across the women’s sector, including Rape Crisis, Women’s Aid, Scottish Women’s Aid, Welsh Women’s Aid, Women’s Aid Federation Northern Ireland, Southall Black Sisters, FORWARD and Everyday Sexism.

We ask MPs to take this opportunity to show their commitment to a world without gender-based violence and to vote to ratify the Istanbul Convention.

Yours sincerely,

Emma Watson, UN Women Global Goodwill Ambassador

Dubravka Šimonović, UN Special Rapporteur on Violence Against Women

Jeremy Corbyn MP, Leader of the Labour Party

Tim Farron MP, Leader of the Liberal Democrats

Caroline Lucas MP, Leader of the Green Party

Nick Clegg MP, former Deputy Prime Minister

Lisa Gormley, Centre for Women, Peace and Security, London School of Economics

Dr Keina Yoshida, barrister Doughty Street Chambers and Advisory Board Member, Centre for Women, Peace and Security, London School of Economics

Dr Susan Atkins, Advisory Board, Centre for Women, Peace and Security, London School of Economics

Laura Bates, Everyday Sexism Project

Polly Neate, CEO, Women's Aid Federation of England

Marsha Scott, Scottish Women's Aid

Jan Melia, Women's Aid Federation Northern Ireland

Jane Connors, Director International Advocacy Programme, Amnesty International

Kate Allen, Director, Amnesty International UK

Alison Gordon, Executive Director, Sisters For Change

Nimco Ali, Daughters of Eve

Peter Grant, Co-director, Restored

Lucy-Ann Holmes, No More Page Three

Laura Bates, Everyday Sexism Project

Sarah Green, Co-director, End Violence Against Women Coalition

Pragna Patel, Director, Southall Black Sisters

Harriet Wistrich, Founder, Centre for Women’s Justice

Jane Gordon, Founder, Sisters for Change

Andrea Coomber, Director of Justice

Professor Clare McGlynn, Durham Law School

Professor Anna Lawson, Director, Leeds University Centre for Disability Studies

Becca Bunce, IC Change

Rachel Nye, IC Change

Robyn Boosey, IC Change

Baroness Mary Goudie

Jess Phillips MP

Tim Brake MP

Alistair Carmichael MP

Norman Lamb MP

Greg Mulholland MP

John Pugh MP

Mark Williams MP

Sarah Olney, incoming MP

Dr Eilidh Whiteford MP

Angus Robertson MP, Leader of the SNP Westminster Group

Gavin Newlands MP

Mhairi Black MP

Angela Crawley MP

Tasmina Ahmed-Sheikh MP

Kirsten Oswald MP

Chris Law MP

Martyn Day MP

Drew Hendry MP

George Kerevan MP

Hannah Bardell MP

Alan Brown MP

Margaret Ferrier MP

Patrick Grady MP

John McNally MP

Owen Thompson MP

Carol Monaghan MP

Mike Weir MP

Callum McCaig MP

Tommy Sheppard MP

Stephen Gethins MP

Peter Grant MP

Patricia Gibson MP

Steven Paterson MP

John Nicolson MP

Pete Wishart MP

Deirdre Brock MP

Kirsty Blackman MP

Neil Gray MP

Ian Blackford MP

Marion Fellows MP

Anne McLaughlin MP

Philippa Whitford MP

Richard Arkless MP

Stuart McDonald MP

Stewart McDonald MP

Alison Thewliss MP

Lisa Cameron MP

Calum Kerr MP