In May 2003, transcripts of telephone calls between McGuinness and British officials including Mo Mowlam, the then Secretary of State for Northern Ireland, and Jonathan Powell, Tony Blair's Chief of Staff, were published in a biography of McGuinness entitled "From Guns to Government" by Kathryn Johnston and Liam Clarke. The tapes had been made by MI5 and the authors of the book were arrested under the Official Secrets Act. The conversations showed an easy and friendly relationship between McGuinness and Powell. He joked with Powell about unionist MPs while Mowlam referred to him as "babe" and discussed her difficulties with Blair. In another transcript, he praised Bill Clinton to Gerry Adams.