Unnamed Tory MPs have said they are being blackmailed by the Chief Whip for voting against gay marriage.
The MPs say their expenses records are being used to “bully” and “victimise” them because they failed to support the Government’s unpopular policy.
Sir George Young, the Tory Chief Whip, is understood to have got the expenses details from the Independent Parliamentary Standards Authority (Ipsa).
One MP has issued a formal complaint to the Information Commissioner, saying that ‘leaked’ travel and housing claims are being used.
That MP, who has not been publicly named, told The Mail on Sunday: “Sir George warned me that I should play ball with Ipsa, or risk personal financial details being made public. I feel that amounted to blackmail.”
Another MP said: “Sir George is trying to find a new way to victimise and bully the rebels.”
In February, more Tory MPs voted against than in favour of Government plans to redefine marriage.
Most MPs were supposed to have a free vote, but behind the scenes there was a lot of arm-twisting.
But a source close to Sir George told The Mail on Sunday: “It is complete paranoid nonsense to suggest that the Chief Whip has in any way used MPs’ expenses difficulties as a way of enforcing discipline. It’s just not his style.
“It is perfectly normal for the Chief Whip to discuss an MP’s expenses with them if there is an issue.
“The information about the expenses of the MP who has complained was not confidential.”
An Ipsa spokesman said it was “perfectly reasonable” for the body to “raise concerns” about MPs with chief whips.