Loyalty, the debut play by writer and journalist Sarah Helm - opponent of the Iraq war and wife of Tony Blair’s then Chief of Staff Jonathan Powell - will premiere at the Hampstead Theatre from 20 July 2011 (previews from 14 July) to 13 August starring Maxine Peake.

A Sunday Times journalist and founding member of The Independent Helm draws on her own experience - which has also seen her write a fictionalised memoir of what it was like to share a husband with the Prime Minister at key moments in the Iraq crisis - to pen the drama where rows over WMD break out at a children’s birthday party, and the audience eavesdrop on the couple listening in to the PM’s phone calls to George Bush.

Shocking revelations about British intelligence finally emerge over a dinner at Number 10, raising disturbing new questions about how a country can be seduced into war.

As a foreign correspondent Helm worked in the Middle East and Washington and reported from Iraq. Winner of Press Awards for foreign reporting and for coverage of official secrets stories, Helm is also the author of A Life in Secrets, a biography of the wartime secret agent Vera Atkins.

Maxine Peake, who will play character loosely based on Helm, has recently been seen in the BBC legal drama Silk. Her extensive television roles including playing Myra Hindley in See No Evil: The Moors Murders, and lead roles in Shameless, Dinnerladies, Early Doors, Little Dorrit, Red Riding and Criminal Justice. Her stage credits include The Deep Blue Sea for West Yorkshire Playhouse, Leaves of Glass at the Soho Theatre, The Cherry Orchard at the National Theatre, Miss Julie at the Theatre Royal Haymarket, Mother Theresa Is Dead for the Royal Court Theatre and The Third Day at the Ambassadors Theatre.

Loyalty will be directed by the Hampstead Theatre's artistic director Edward Hall with design by Francis O'Connor, lighting by Ben Ormerod and sound design by Paul Groothuis. Full casting for the production is still to be announced.