As G4S management and shareholders prepare to participate in the G4S AGM on Thursday, we call on G4S management and shareholders to end the corporation's participation in Israel's brutal occupation. G4S operates and maintains security systems at the Ofer prison, located in the occupied West Bank, and for the Kishon and Moskobiyyeh detention/interrogation facilities, at which human rights organisations have documented systematic torture and ill-treatment of Palestinian prisoners, including child prisoners, held in solitary confinement.

G4S helps the Israeli prison service to run prisons inside Israel that hold prisoners from occupied Palestinian territory, despite the fourth Geneva convention prohibition of the transfer of prisoners from occupied territory into the territory of the occupier. Through its involvement in Israel's prison system, G4S is complicit in violations of international law and participates in Israel's use of mass incarceration as a means by which to dissuade Palestinians from protesting against Israel's systematic human rights abuses.

G4S also provides equipment and services to the Israeli military checkpoints in the West Bank that form part of the route of Israel's illegal wall and to the terminals isolating the occupied and besieged territory of Gaza. G4S's role in Israel's brutal occupation and abhorrent prison system is unacceptable and must end. Join our call – add your name to this letter on the War on Want website.

Archbishop Desmond Tutu, Ahmed Kathrada South African politician and former political prisoner, Alexei Sayle Comedian, Alice Walker Author, Angela Davis Author and activist, Breyten Breytenbach Poet and painter, John Berger Author, Ken Loach Director, Michael Mansfield QC Barrister, Mike Leigh Director, Miriam Margolyes Actor, Noam Chomsky Philosopher and author, Paul Laverty Screenwriter, Professor Richard Falk Professor of international law, Roger Waters Musician, Saleh Bakri Actor

• More than 200 Palestinian children are being held in Israeli prisons. At least two of the jails where Palestinian children are detained – Ofer in the West Bank and Al Jalame in Israel – are supplied with security systems by G4S.

Several organisations, including Unicef in 2013, have documented the ill-treatment of the children inside these prisons. Unicef reported that the abuse of Palestinian youngsters trapped in the Israeli prison system is "widespread, systematic and institutionalised". At its AGM last year, a number of concerned shareholders questioned the G4S board about the company's complicity in the detention and abuse of Palestinian children, eliciting the promise of a review of the current situation.

A year on, G4S appears to be as entrenched as ever in the Israeli prison system. This is an unacceptable position for the company, with its headquarters in the UK, to be in. We call on G4S to show it has a conscience and terminate its contracts with facilities where children suffer routine physical and verbal abuse, contrary to the norms of civilised society.

Jeremy Corbyn MP, Andy Slaughter MP, Grahame Morris MP, Richard Burden MP, Katy Clark MP, Chris Williamson MP, Alex Cunningham MP, John Denham MP, Caroline Lucas MP, Paul Blomfield MP, Crispin Blunt MP, Joan Ruddock MP, Mark Durkan MP, Roger Godsiff MP, Hugh Lanning Chair, Palestine Solidarity Campaign, Geoffrey Bindman QC, Bruce Kent CND, Caryl Churchill Playwright, Victoria Brittain Journalist and author, Rev Canon Garth Hewitt Amos Trust, Professor Steven Rose, John Austin, Betty Hunter