Conservative Party leader David Cameron today refused to release a full breakdown of his second home expenses to the Oxford Mail - but insisted he would be happy for them to be published by the Commons authorities.

The Commons Commission, which manages House affairs, has come under fire for challenging a ruling, on security grounds, that the details of 14 MPs' second home allowances, including Mr Cameron's, be released along with their addresses.

Mr Cameron's spokesman revealed that almost all the cash the Oxfordshire MP has claimed for his constituency home near Chadlington under the Additional Costs Allowance - £20,563 in 2006-7 - was for mortgage interest payments.

Mr Cameron is concerned that unilaterally publishing his own details in full would undermine the authority of the Commons Commission and its chairman, Speaker Michael Martin.

His spokesman said: "Obviously David Cameron wants a speedy resolution to this problem and wants the information released. But the overall release is a matter for the committee."