While 177 of 303 Conservative MPs abstained or voted against same sex marriage on Tuesday, the MPs for Horsham and the South Downs voted in favour.
Both have said they believe the Bill opens up a key institution to more people, while protecting the rights of religious organisations in several ways.
Nick Herbert (Arundel and South Downs) is in a civil partnership with a long term partner.
Francis Maude (Horsham) saw his 42-year-old brother die of Aids in 1993.
Mr Maude said: “Marriage in the 21st century is now an inclusive, not exclusive, institution.
“It is available to all adults who are prepared to state publicly their commitment to each other.
“ Except, that is, if you happen to love someone of the same sex.
“I don’t think this is right,’’ said Mr Maude.
“The state cannot justify preventing people from marrying unless there are extremely good reasons for doing so.”
Mr Herbert spoke in Parliament on Tuesday of the work that still needs to be done to ensure people feel able to ‘come out’ knowing they will be accepted by friends and family.
He said: “The signal we send today about whether the law fully recognises the place of gay people in our society will really matter.
“Above all, I think of two people, faithful and loving, who simply want their commitment to be recognised, as it is for straight couples.
“That, in the end, is what this Bill is about.”
The Bill will now be considered in the House of Lords