CROYDON South MP Richard Ottaway this week announced his support for gay marriage.
The Tory had previously been undecided on the controversial issue when quizzed by the Advertiser.
But following "several discussions with constituents", including members of the Church and teachers in faith schools, Mr Ottaway has made his position clear.
"Society has come a long way on the subject of sexual equality," the MP said.
"As a member of the Conservative party and of the Church of England I am intensely aware of the reservations that exist. However, we should recognise that the historical success of both of these institutions has been due to their willingness to evolve as society evolves."
Mr Ottaway, who will step down from his post at the next general election added: "Young people, the polls tell us, are overwhelmingly in favour of the proposals and simply don't understand the opposition of the older generation. "Perhaps this is because they have not lived before the 1967 Act, so sexual orientation is not a big deal. "I see no reason, as I approach retirement from politics, to disrespect their view of what is normal today. "We should not stand in the way of a younger generation that clearly wants this reform."