Milton was selected to contest the Guildford parliamentary constituency in the 2005 general election, a seat which the Conservatives had unexpectedly lost in 2001 to the Liberal DemocratSue Doughty with the constituency becoming a marginal. She was elected as the MP for Guildford at the 2005 general election with a margin of victory of 347 votes. After the election, she was appointed to the Health Select Committee serving till December 2006. During the 2005-2010 parliament, Milton worked as the Shadow Minister for Tourism from November 2006 and then the Shadow Minister for Health in July 2007. In February 2006, Milton was among a minority of Conservative MPs to oppose exceptions for private clubs from the proposed Smoking ban in England. Milton had previously announced her opposition to a partial ban, stating it was "the worst possible solution". Milton held her seat in the 2010 general election and increased her majority to 7,782 votes. In July 2010, Milton suggested that doctors should describe obese patients as 'fat' to encourage them to take responsibility for their condition. This was criticised by campaigners who pointed out that a clinical definition was being replaced with a subjective, pejorative term. During the 2010-2015 parliament, she served as Parliamentary Under-Secretary at the Department of Health, then, as a result of a ministerial reshuffle in September 2012, Milton was appointed a Government Whip, Vice-Chamberlain of the Household and later Treasurer of the Household. She abstained on the parliamentary vote on the legalisation of same sex marriage in February 2013 citing a lack of consensus amongst her constituents. In March 2015, she was appointed to the Privy Council of the United Kingdom and therefore granted the title The Right Honourable. She voted for the United Kingdom to remain with the European Union in the June 2016 membership referendum. Milton was re-elected as MP for Guildford in the 2017 snap general election. After the election, she was selected as the Minister of State for Skills and Apprenticeships and the Minister for Women. On 23 October 2018, Milton resigned from the Commons Reference Group on Representation and Inclusion, chaired by Commons speaker John Bercow, citing incompetence in Bercow's ability to tackle bullying and sexual harassment problems in Parliament. On 23 July 2019, Milton resigned as Minister of State for Skills and Apprenticeships shortly before Boris Johnson was announced as the new leader of the Conservative Party and, thus, Prime Minister. She said that she could not serve in a government which said there was a possibility of the UK leaving the European Union with no deal.
Personal life
She married Neil Milton in 1979 in Haywards Heath; the couple later divorced. Her current husband, Dr. Graham Henderson, whom she married in February 2000 in Surrey, is a former local medical director at Virgin Healthcare. Milton lives in Surrey and has four children, one of whom is yachtswoman Nikki Henderson.