Labour leader Andrew Little got a small pay rise in switch from union boss to backbench MP.

Labour Leader Andrew Little has released his tax returns going back to 2010 showing he earned just over $130,000 in his former role as the head of the EPMU.

The records show he paid tax of $40,165 in the 2010 year, but had no other income outside his salary.

That patterns continued in the following years although his income jumped to $226,114, with tax of $65,985 in 2011 - the year he quit the EPMU - reflecting back pay and holiday pay.

As an MP he earned earned just over $143,000 but that jumped to $189,000 in 2014/15 including the pay rise he received when he became Labour leader.

His spokeswoman said he also received a small amount of interest income on his savings, but that was taxed at source.

Little said her had released his records because transparency was crucial for public confidence in political leaders.

"I have no qualms in releasing my history of tax payments because I believe New Zealanders want to know that those at the top are paying their full fair share and are not protecting those who are not," he said.

"British PM David Cameron has done it to allay fears that he has been tax dodging. I think it is important that our Prime Minister does the same."

Prime Minister John Key has said he has no intention of releasing his tax records, but has said he is "100 per cent confident" his tax affairs are beyond reproach.

Little said for the past week Key had seemed to protect the world's global rich who hide their wealth in New Zealand and fail to pay tax.

"After public pressure, he has done the bare minimum and asked a single tax consultant to review our laws behind closed doors with only the narrowest terms of reference. The question is why it has taken him so long to act, why is the inquiry a white-wash before it has begun and what does he have to hide by downplaying New Zealand's tax haven reputation?"

He said full transparency was the only thing that would restore public confidence in the tax regime.

"John Key must do the right thing and make public his own tax record."

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