Conservative MP and Business Minister Michael Fallon has conceded that he was wrong to vote against the Marriage (Same Sex Couples Bill) and says opponents should accept this week’s decisive Commons verdict.

On Tuesday, the bill was backed by MPs with a majority of 225.

However, David Cameron’s personal authority was left weakened. 136 Conservatives – almost half of the party’s MPs – opposed the bill.

Michael Fallon, the MP for Sevenoaks in Kent and a former deputy chairman of the party was one of several middle ranking and junior ministers who voted against. They included: John Hayes, Greg Knight, David Lidington, Esther McVey, Mike Penning, John Randall and Andrew Robathan.

On Wednesday, Mr Fallon told the BBC’s Daily Politics programme that the Conservative Party now had to unite.

“Well it was a free vote, it wasn’t a political thing, it wasn’t a government thing,” Mr Fallon said. “The whole point of a free vote is it’s free and it’s up to each member and each minister to vote according to their own conscience and what they felt about the matter.”

He continued: “I think it would’ve been pretty scornful if he had announced a free vote and then 95% of Conservative MPs trooped into the Lobby behind him. There were divisions in the party, there are divisions in the country. I voted against because I think if you’re going to redefine marriage, one of the central institutions of our society, you probably need to do so on the basis of a lot more consultation for that change than I thought existed at the moment.

Mr Fallon added: “But I was wrong, the majority of people in parliament have voted the other way and we’ve got to accept that now and make this thing work.”

Conservative MP Adam Afriyie, who has recently been seen by some as a future successor to David Cameron, has offered his reason for not supporting the bill by saying it “unnecessarily creates two forms of legally recognised union.”