http://www.legislation.gov.uk/id/ukpga/1989/28

http://www.legislation.gov.uk/ukpga/1989/28/section/1

Representation of the People Act 1989

An Act to amend the law relating to the entitlement of British citizens resident outside the United Kingdom to vote at parliamentary elections and elections to the European Parliament and to increase the maximum amount of candidates’ election expenses at parliamentary by-elections.