In 1974 Whittle came out as a FTM trans man, after returning from a women's Liberation Conference in Edinburgh, which he attended as a member of the Manchester Lesbian Collective. He began hormone replacement therapy in 1975. He has been active in transsexual and transgender communities since the age of twenty when in 1975 he joined the Manchester TV/TS group which had been started in 1972/3 by two trans women the very first support group for transsexual people in the United Kingdom. In 1979 he joined a former army officer and then royal sculptor, Judy Couzins, a trans woman in the Self Help Association for Transsexuals (SHAFT). In 1989, he founded the UK's FTM Network which he coordinated until November 2007. In 1992, along with Mark Rees, the actress Myka Scott and an airline pilot Krystyna Sheffield, he founded and became vice-president of Press for Change that works to change the laws and social attitudes surrounding transgender and transsexual lives. Whittle remains as one of the vice-presidents (there is no president, as it is a consensus group), and Press for Change was called "one of the most successful lobby groups seen in the last 25 years" by Lord Alex Carlile, Baron Carlile of Berriew as early as 1994 at the reading of his Gender Reassignment Bill. The bill failed but "for 40 minutes members of parliament discussed trans people which without it, would have never happened." Whittle underwent phalloplasty surgeries from 2001 to 2003. The Channel 4 documentary Make me a Man followed his life during the surgeries. Though unable to marry legally in the United Kingdom until the passing of the Gender Recognition Act 2004, he and his partner (now wife), Sarah Rutherford, have four children by artificial insemination. Whittle wrote in Disembodied Law: Trans People's Legal(Outer) Space, "I face an inadequate legal framework in which to exist. We are simply 'not' within a world that only permits two sexes, only allows two forms of gender role, gender identity or expression. Always falling outside of the 'norm' our lives become less, our humanity is questioned, and our oppression is legitimized." The Whittles' efforts to gain recognition of Stephen as their children's legal father led to X, Y and Z v. The United Kingdom before the European Court of Human Rights in 1996. When the Gender Recognition Act 2004 came into force in April 2005, Whittle obtained a new, male