Update: The final figures show that 136 Tories voted against the bill, with 127 voting in favour and 40 abstaining. In other words, the majority of Conservative MPs failed to support equal marriage.
With the outcome of the vote on equal marriage never in doubt (MPs voted in favour of the bill by 400 to 175), the key question was always how many Conservatives would oppose the measure.
Based on initial reports, it appears that 139 Tory MPs  voted against the bill, with 132 voting in favour. Were this not a free vote, the Tories would have equalled the largest postwar rebellion - the Iraq war vote in 2003. If accurate, the figures are disastrous for David Cameron. More than half of his MPs (of which there are 303 excluding speakers) chose either to oppose the measure or to abstain.
The Prime Minister hoped to use the vote on equal marriage to demonstrate how much his party has changed but he has ended up achieving the reverse. While ministers will point out that this was a free vote and so technically not a "rebellion", there is no disguising the fact that more Tory MPs opposed Cameron's position than supported it. That is a blow to his personal authority and to his claim to have "modernised" the Conservative Party.