She received greater attention when she featured in the low-budget film "Letter to Brezhnev" (1985), the screenplay being adapted by her brother from his own play. It concerns two working class Liverpool girls who meet two Russian sailors. The film was made for around £50,000 (Clarke called this "the cocaine budget on "Rambo""), and became an international hit. At the next "Evening Standard British Film Awards", Clarke was awarded the prize for "Most Promising Newcomer". Margi originated her role of Theresa in "Letter to Brezhnev" a few years earlier when she played the role in a modest run at the Liverpool Playhouse in 1983.