The Conservative MP for Arundel and South Downs, Nick Herbert, has led the campaign in Parliament for sex-same marriage.
The North Thanet MP Sir Roger Gale is one of the fiercest critics of same-sex marriage.
The Banbury MP Sir Tony Baldry has spoken about his opposition to same-sex marriage. He speaks in the Commons on behalf of the Church of England, as Second Church Estates Commissioner.
The Conservative MP for East Worthing and Shoreham Tim Loughton - the former Children's Minister - has voiced his opposition to same-sex marriage. He intervened in a speech by Labour's Equalities spokesperson Yvette Cooper.
The debate on legalising gay marriage has begun in the House of Commons. The Culture Secretary, Maria Miller, who is the MP for Basingstoke, has been explaining the legislation.
She faced questions from MPs, including Rehman Chishti (Gillingham and Rainham), Caroline Lucas (Brighton Pavilion), Sir Gerald Howarth (Aldershot) and Julian Brazier (Canterbury).
MPs from the South will today vote on proposals to legalise same-sex marriage. If passed, the bill would allow religious organisations to marry gay and lesbian couples. Last week, Reading East MP Rob Wilson held a meeting in the town to ask his constituents' views on the issue.