Along with everyone else. It's a privilege previously reserved for MPs, peers, certain parliamentary officials and their families:
"Westminster City Council has granted a licence approving two rooms in the Palace of Westminster to be used for marriages and civil partnerships…The rooms have been approved as venues for civil ceremonies until 2013.
The Jubilee Room, which overlooks Cromwell Green, has space for 80 people and the MPs' dining room, with views of the Thames, has space for 150."
The new guidelines still rule out use of the 14th century Chapel of St Mary in Parliament as sites for civil partnerships or civil marriages.