Cressida Dick has been accused of calling for “more black boys” to be locked up after suggesting that harsher jail terms should use to deter teenagers driving a spate of knife crime in London.

The Metropolitan Police Commissioner, who is Britain’s most senior police officer, made the comments to campaigners, prison governors and academics gathered at a charity event.

Ms Dick voiced concern over a spike in stabbings in London, which have risen by more than 15 per cent so far this year and seen 16 teenagers among those murdered using knives.

“I haven't come here to argue for putting more children in prison…but I'm seeing them commit serious offences in increasing levels of violence and increasing numbers, and I have to be realistic,” the Commissioner said.

“We need a blend of better engagement by public services, more diversion and more imaginative community resolution to help keep as many young people out of prison as possible.

“For debate, should we couple that with harsher more effective sentencing? It is clear other approaches are no longer working.”

Ms Dick said young black men and boys were statistically more likely to be the victims and perpetrators of knife crime, making up 21 of 24 teenagers murdered so far this year.

The deadly spate of stabbings shows no sign of slowing, with a 21-year-old man murdered in Newham on Wednesday and a 17-year-old boy stabbed to death in Penge last week.

17-year-old Michael Jonas was stabbed to death in Penge, south-east London, on 2 November (Metropolitan Police)

Ms Dick said the crime wave was being driven by a “core group of young offenders” repeatedly committing assault and robbery “with relative impunity”.

The Commissioner cited the case of a 16-year-old boy from south London who has committed 42 separate crimes including assault and drugs offences in three years, carries a knife, is involved in gangs, but has never been jailed.

“He's a child - he's our responsibility and we have to ask ourselves what is it about the system that isn't working?” Ms Dick said.

“Why is he offending so much and how is he able to? And he is by no means alone.”

She argued that an increasing number of young people do not fear state action and are not deterred by the threat of imprisonment because they do not believe theywill be jailed, or that it would be for a short time.

Ms Dick had been invited as a guest speaker by the Howard League for Penal Reform, which campaigns for fewer people to be jailed and highlights poor conditions and failures within the criminal justice system.

Frances Crook, the charity’s chief executive, said the Commissioner had “used the opportunity to call for more young children, in effect more black boys, to be sent to prison and for longer”.

In a damning response, she said Ms Dick “did not deliver a lecture - it appeared to be more a few unconnected thoughts presented as challenges to the audience”.

Ms Crook added: “It was rather surprising that the head of the Met chose not to talk about things that are within her power to act on, but instead to focus on areas outside her expertise and responsibility, particularly when there are some good stories to tell about the work of her organisation.”

While Ms Dick argued that prison protects the public from dangerous people, she admitted that two out of three teenagers go on to reoffend within a year of their release.

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

“We also know that many of the perpetrators of violent crime are also victims of violent crime and vice versa,” she added.

One in three robbery victims is aged 10 to 19, while the 26 per cent of rape victims are in the same age group, along with 16 per cent of sexual offenders.

“We need to step in earlier into people's lives,” the Commissioner said. “We need to give more real deterrents and we need to use the opportunity that imprisonment could give to better ensure that children, and we must remember they are children, don't reoffend.”

A HM Inspectorate of Prisons report found that not one youth jail in England and Wales is currently safe, after a “staggering rise” in violence, easy access to drugs and declining emphasis on rehabilitation.

A separate report by Labour MP David Lammy also found that black people in the UK are proportionally more likely to be imprisoned than those in the US.

Andrew Neilson, director of campaigns at the Howard League, said that authorities should not be locking young offenders up “for the remainder of their childhoods in institutions that have been deemed unsafe”.

“There is no evidence that more prison sentences will actually work,” he told The Independent.

“Knife crime was falling when mandatory sentences for knife possession were introduced a few years ago, and now it’s rising.

(ONS (ONS)

“So it doesn’t necessarily follow that her proposals would stop the knife crime epidemic.”

Mr Neilson said that while the head of the Metropolitan Police cannot directly make sentencing decisions, “anything she says carries weight” and the intervention could influence politicians who can spark new laws.

He added: “What [Ms Dick] is talking about is a change to a national sentencing policy, and I would question whether that should be changed by a local trend in London, however serious that is.”

The campaigner described a vicious cycle, where increases in crime have driven lengthened sentences and a rising prison population, which in turn has worsened conditions and led to riots and violence.

“The solutions to this are not going to lie in the criminal justice system - they might manage things slightly but they won’t stop the underlying reasons why these gangs are running rampant,” Mr Neilson added.

The debate came after the Metropolitan Police released guidelines to officers allowing them to stop investigating some lower-level crimes as the force works to save £400m by 2020.

An efficiency report released by the HM Inspectorate of Constabulary this week warned that police across the country were struggling to maintain a full response because of “significant stress” caused by continued spending cuts amid a huge rise in demand.