Mr Woodward was one of the most high-profile New Labour figures who opposed a reduction in MP London living allowances and the introduction of external auditing of claims.

Prime Minister Gordon Brown expressed disappointment at the outcome of last week's Commons vote, but has been attacked over the position adopted by Ministers like the Northern Ireland Secretary.

Mr Woodward has also been singled out for criticism, due to his own personal wealth.

An aide, however, said he supported reform but did not believe the proposals put before the House on Thursday night were the right way forward.

The package voted down by the Commons would have replaced the £24,000-a-year London living allowance with a new overnight expenses system with a £19,600 ceiling.

It would also have halted claims for furniture and household goods for MPs' taxpayer-funded homes in London.

In addition, outside audits of MPs' expenses would have been introduced, along with a requirement for receipts for claims under £25.

The proposals had been drawn up by the cross-party Members Estimate Committee, chaired by Speaker Michael Martin.

The Taxpayers' Alliance hit out at Mr Woodward, with campaign director Mark Wallace saying: "It's pretty shocking for anyone to go against these changes, but appalling for someone like Shaun Woodward."

Mr Woodward is one of the richest MPs in the Commons. His wife Camilla is a Sainsbury's heiress and he has property interests in different parts of the world.

But an aide said the Ulster Secretary did not believe the proposed expenses changes were satisfactory and felt the plan for outside auditing would be expensive and overly-bureaucratic.

"He feels that further reforms should be looked at as quickly as possible.

"A proper set of proposals with the appropriate transparency and scrutiny can be voted on, which avoids any new bureaucracy which would be costly to taxpayers.

"He believes that MPs are inherently honest and hard-working and should be entitled to claim legitimate expenses."

Mr Woodward claimed £22,110 in London living expenses in 2006/07 — the maximum total available for that year.

Most MPs use the allowance to fund second homes in the city.

It can also be used to claim for such items as furniture.