Suspended Labour MP Chris Carter is taking two months of taxpayer-funded sick leave from Parliament, after last week denying he was unwell.

But his friends say he is stressed and exhausted - not mentally unbalanced or having a nervous breakdown, as other colleagues have implied.

The leave will delay Labour's disciplinary action against him which was due to start at the party's New Zealand Council meeting in Wellington on Saturday.

Mr Carter last week sent anonymous notes to press gallery journalists suggesting Phil Goff's leadership of the party was in trouble and he would be challenged before the next election.

He subsequently publicly attacked Mr Goff as unable to win the election and said he hoped Labour MPs would be remove him as leader.

Prime Minister John Key said yesterday he did not believe Mr Carter was unwell but rather that he was saying what most of his party's MPs thought.

MPs can have up to 14 sitting days off without the permission of the Speaker before facing any sanctions.

Because Parliament sits only three days a week, and taking into account the two-week recess, Mr Carter could stay away until September 16, before requiring the Speaker's permission.

If he were absent without leave after that, his pay of about $2800 a week would be docked by $10 a week.

He does not need the permission of the Labour whip or leader to be away because he is no longer a member of the caucus.

News of Mr Carter's two-month sickie surprised Employers and Manufacturers Association chief executive Alasdair Thompson.

He described it as "extraordinary" that Mr Carter could be docked only $10 a week for being absent without leave.

While many employers were willing to help staff requiring extended absences from work, it would generally need to be for a "diagnosed" illness.

New Zealand workers get up to 10 days paid sick leave a year.

Mr Thompson said that although he did not have a great problem with Mr Carter taking time off, he would not want to see him taking advantage of the rules. If he were to be absent for an extended period he should consider "doing the decent thing" and retiring from Parliament.

Mr Goff said: "If he is unwell, that partially explains his actions but it does not justify them or excuse them."

Labour president Andrew Little said the party was pleased that Mr Carter "is getting the help he needs."

The New Zealand Council would still discuss the Carter issue at its meeting in Wellington this weekend.

Mr Carter did not return calls yesterday. A friend answered his phone at home and said he needed to rest because he had been stressed and exhausted.