Lord Dartmouth worked as a chartered accountant (FCA 1975), also the occupation of his father Gerald Legge, 9th Earl of Dartmouth, whose titles he inherited in 1997. As Earl of Dartmouth, he sat as Conservative peer in the House of Lords until 1999, when the Labour government of Tony Blair removed all but 92 hereditary peers from Parliament. In January 2007, Dartmouth announced he was leaving the Conservative Party in favour of the UK Independence Party (UKIP), citing concerns about the policies of David Cameron (then Leader of HM Opposition).