BAFTA award-winning Anna Maxwell Martin (Freefall, White Girl, Bleak House) plays journalist and campaigner Heather Brooke, whose tenacious investigations brought about the disclosure of MPs’ expenses, in one-off drama On Expenses for BBC Four. Brian Cox (The Bourne Supremacy, Troy) stars opposite Anna as Speaker of the House of Commons Michael Martin, who finds himself in a battle against Heather when she requests details of MPs’ expenses and allowances under the Freedom of Information Act.

Written by Tony Saint (The Long Walk to Finchley, Micro Men), and directed by Simon Cellan Jones (Generation Kill, The Trial Of Tony Blair, Our Friends In The North), this humourous 60-minute drama focuses on the events leading up to one of the defining political scandals in recent history, and reveals the David and Goliath tale behind the now infamous headlines.

Simon Cellan Jones says: “Everyone knows about the Telegraph scoop, but this is the story behind it and we wanted to tell it. It isn’t a party political piece – it’s the story behind the story.”

An American journalist living in the UK, Heather Brooke doggedly fought for details of MPs’ expenses under the Freedom of Information Act after her legitimate requests were declined by the House of Commons.

Taking her case all the way to the High Court, Brooke won the case against the House of Commons – but heartbreakingly lost the scoop.

Simon Cellan Jones continues: “I think this is going to set the story straight about how the news story came about. It also shows the lengths to which the House of Commons suppressed the story in the interest of trying to protect the MPs.

“I hope it will evoke a mixture of shock and laughter. It’s quite a surreal story in that the people who voted in the Freedom of Information Act were the very people that tried to get themselves exempt from it.”

On Expenses also stars Alex Jennings as Fees Office head Andrew Walker, the man in charge of approving MPs’ expenses; Tim Pigott-Smith (Quantum Of Solace, North And South) as Labour MP Alan Keen; and Neil Pearson (The State Within, Bridget Jones) as Hugh Tomlinson QC, who successfully led the legal campaign to force the Commons to publish the claims.