We write to express our deep concern for the family of Sayed Ahmed Alwadaei, director of the Bahrain Institute for Rights and Democracy (BIRD). Mr Alwadaei was granted refugee status in the UK in 2012 in recognition of the dangers he faced in Bahrain. While in London, Mr Alwadaei has continued to fight for the rights of torture victims and prisoners sentenced to death for peacefully protesting against the Bahraini regime. The family of Mr Alwadaei has been subjected to numerous human rights violations by the Bahraini authorities in response to BIRD’s work, including arbitrary detention, unfair trial, ill-treatment and possible torture.

The United Nations working group on arbitrary detention concluded that Mr Alwadaei’s family were “deprived of their liberty, interrogated and prosecuted for their family ties with Sayed Ahmed Alwadaei and that these were acts of reprisal”. The Bahraini government responded with a smear campaign of false and misleading information about Mr Alwadaei and his family.

Such abuse is an attempt to intimidate Mr Alwadaei to prevent him from continuing his work. This has been condemned by over 80 members of the UK parliament.

The British government has repeatedly committed to support human rights defenders. It must condemn the persecution of Mr Alwadaei and his family, assert his right to criticise abuses in Bahrain, and advocate for the release of his unlawfully detained family members. Security assistance to Bahrain should be conditional on Bahrain’s adherence to its international human rights obligations.

Maya Foa Director, Reprieve

Kate Allen UK director, Amnesty International

Jodie Ginsberg CEO, Index on Censorship

Antonia Byatt Director, English PEN

Rebecca Vincent UK Bureau Director, Reporters Without Borders

Rowan Kinchin Director, Campaign Against Arms Trade

Jago Russell Chief executive, Fair Trials

Saloua Ghazouani Oueslati MENA Director, Article 19

Rupert Skilbeck Director, Redress

Joe Stork Chair of the Advisory Board, the Gulf Centre for Human Rights

Husain Abdulla Executive director, ADHRB

Brian Dooley Human rights campaigner

Stephen Knafler QC Landmark Chambers

David Lock QC Landmark Chambers

Tim Buley Landmark Chambers

Jane Deighton Founding partner of Deighton Pierce Glynn

Daniel Carey Deighton Pierce Glynn

Stephen Cragg QC Doughty Street Chambers

Tim Cooke-Hurle Doughty Street Chambers

Chris Henley QC Carmelite Chambers; chair of Criminal Bar Association

Sheona York Clinic solicitor and reader in law, University of Kent

Angela Jackman Senior lecturer, City Law School

Dr Sam Raphael Senior lecturer, International Relations, University of Westminster

Tony Fisher Fisher Jones Greenwood

Prof Juan E Mendez Former United Nations special rapporteur on torture

Martyn Day Founder of Leigh Day

Astrid Perry Leigh Day

Saimo Chahal QC Bindmans LLP

Dan Squires QC Barrister, Matrix Chambers

Samantha Knights QC Refugee and human rights barrister, Matrix Chambers

Hugh Southey QC Human rights barrister, Matrix Chambers

Daniel Machover Head of civil department, Hickman & Rose Solicitors

Peter Bottomley MP Conservative, Worthing West

Fiona Bruce MP Conservative, Congleton

Ian Blackford MP SNP Westminster leader

Paul Scriven Liberal Democrat, House of Lords

Ed Davey MP Liberal Democrat, Kingston and Surbiton

Christine Jardine MP Liberal Democrat, Edinburgh West

Alistair Carmichael MP Liberal Democrat, Orkney and Shetland

Tom Brake MP Liberal Democrat, Carshalton and Wallington

Andy Slaughter MP Labour, Hammersmith

Jim Cunningham MP Labour, Coventry South

Jo Swinson MP Liberal Democrat, East Dunbartonshire

Matt Western MP Labour, Warwick and Leamington

Alex Norris MP Labour, Nottingham North

Lloyd Russell-Moyle MP Labour, Brighton Kemptown

Catherine West MP Labour, Hornsey and Wood Green

Philippa Whitford MP SNP, Central Ayrshire

Angus MacNeil MP SNP, Na h-Eileanan an Iar

Stephen Gethins MP SNP, North East Fife

Chris Law MP SNP, Dundee West

Stuart McDonald MP SNP, Cumbernauld, Kilsyth and Kirkintilloch East

Martyn Day MP SNP, Linlithgow and East Falkirk

Caroline Lucas MP Green party, Brighton Pavilion

• Additional signatories were added to this letter on 12 April 2019. An incomplete list had been submitted to the Guardian.