Labour MP Chris Carter has been cautioned by colleagues over recent years to cut down on his overseas travel, the Weekend Herald understands from several sources.

An unrepentant Mr Carter yesterday defended his ministerial travel bill from last year as Education Minister, which was $83,000 for the first six months, and his parliamentary spending bill so far for this year, which is $82,000, as Labour's foreign affairs spokesman and MP for Te Atatu.

So far this year Mr Carter has spent $57,137 on airfares (this does not differentiate between domestic and international), $14,476 on surface travel and $10,667 on Wellington accommodation between January and June.

He is the second-highest spending non-minister behind Labour leader Phil Goff, and as minister had some of the biggest travel bills in Cabinet behind the Prime Minister and Foreign Minister.

His travel costs are boosted because he frequently takes his partner of 35 years, Peter Kaiser, with him.

MPs and their spouses have unlimited domestic air travel and unlike ministerial travel, the purpose of their travel does not have to be work-related.

Because of his long service, Mr Carter also qualifies for a 90 per cent discount on all international trips, whether they are related to work or not, and there is no cap on the rebate.

He has not responded to requests to say how much he spent on those in his last term as a minister - they would most likely have been holidays.

Now that he has no ministerial travel, his overseas travel for work and holiday will be funded by Parliament.

Mr Carter defended his recent month-long trip to the US, Britain, Canada and China and said as his party's foreign affairs spokesman, he would be doing a lot more travelling.

He said he was not an extravagant spender, pointing to his early model Suzuki hatchback.

Mr Carter said he did not get around on a "magic carpet" and that all the travelling as a minister was on "Government business" that had been approved by the Cabinet.

Mr Carter said his partner stayed in his hotel room and is a "moderate eater".

"I'm aware that using the privileges of parliamentary office is going to be scrutinised more closely and if that means that I have to travel more often on my own then I will do that," Mr Carter said.

He cut the press conference short by walking away from media.

On Thursday, Mr Carter wrote a blog on the subject of his expenses, despite acknowledging that the caucus had "made a decision" that only Trevor Mallard, the party whips and leader would comment on expenses.

"I'm loyal and - hard as it's been to resist persistent baiting from journalists to 'stop hiding' - I've been a loyal team player and remained silent," Mr Carter said.