Sir Roger Douglas says he is entitled to a holiday in Britain at the taxpayers' expense.
The ACT MP, who has been vocal in his demands for the Government to cut public spending and for Kiwis to tighten their belts during the recession, has one of the highest airfare bills among MPs.
Figures released by Speaker Lockwood Smith yesterday show Douglas spent $44,411 on air travel in the first six months of this year - the most of any MP who is not a minister except Labour's Chris Carter.
Douglas said much of the bill was for a trip to Britain he took with his wife this year.
He said he was entitled to it and bristled at suggestions he was a hypocrite.
"It's exactly like [former prime ministers] Helen Clark, Jenny Shipley, Mike Moore and others. I'm entitled to claim back 90 per cent of my overseas travel, and I did that for a trip to the UK which I did with my wife," he said.
"If I had not been an MP I would still have been able to claim that money."
MPs elected to Parliament before 1993 and who served three terms receive a discount of 90 per cent on their international airfares for the rest of their life.
Douglas said his trip was not all holiday, "but certainly it was largely a private trip".
"I spent some time with my son and my grandchildren," he said.
"That was granted to us by the Remuneration Authority a long time ago. That was a tradeoff that they made at the time. They said less wage increases for MPs in return for certain entitlements."
Asked if he saw any hypocrisy in his trip, given he was a critic of Government spending, Douglas said: "Listen, my friend, this is a right that Helen Clark has, Jim Bolger has - it's something that I would be able to do if I was an MP or not. Thanks." He then walked off.
Douglas spent more than his leader, Local Government Minister Rodney Hide, who spent $34,841 on air travel.
A spokesman for Hide said expenses varied from MP to MP and he was "not overly concerned" about Douglas' travel bill. "His major issue is greater transparency and he is pleased these figures have come out."
Labour said Carter's travel bill was unusually high because of international visits as the party's foreign affairs spokesman.
Carter spent $57,137 on domestic and international travel, more than Labour leader Phil Goff, who spent $35,000.
Labour's spokesman on the expenses issue, Trevor Mallard, said Carter "has been to the US, UK, China and Canada representing the Opposition on foreign affairs he is a hard-working member".
Like all MPs, Carter's bill includes travel by his partner, but these expenses are not separated.
Mallard said spouses should not be scrutinised in the same way as their MP partners.
Goff's total travel and accommodation bill was the highest of Labour's MPs at $124,000. This was largely because he is entitled to a Crown limousine.
- By COLIN ESPINER, The Press
Is Andrew Little a good choice to lead Labour?