He became the party 's Home Affairs spokesperson in 2003 .
Born in Watford , Hertfordshire , Oaten became a councillor in local government , joining the centre - left Social Democratic Party , which merged with the Liberal Party to form the Liberal Democrats in 1988 .
Oaten became the party 's Home Affairs spokesperson in 2003 .
Born in Watford , Hertfordshire , Oaten became a councillor in local government , joining the centre - left Social Democratic Party , which merged with the Liberal Party to form the Liberal Democrats in 1988 .