UPDATED: 4.29PM Prime Minister John Key is refusing to take any responsibility for the actions of his long time personal lawyer Ken Whitney's lobbying efforts.

It emerged last week that Whitney had lobbied the government in 2014 because of concerns the foreign trusts regime was about to change.

In a letter to then-Revenue Minister Todd McClay in December 2014, Whitney said the PM had told him the government had no plans to tighten the rules for the industry.

The review of trusts was shelved after McClay met with a lobby group headed by Whitney.

Key said yesterday that Whitney has misrepresented him in an email to Todd McClay, however today he said Whitney was just sloppy.

"He is absolutely confident my version of events is correct, and that's what he intended to write in the email and maybe the email was sloppily written if that was the case," Key said.

Current Minister of Revenue Michael Woodhouse claims he's never been lobbied by Whitney, and put the quick response of the minister at the time down to the time of year.

"I have had correspondence with people who are part of that group that were interested in the issue. There's a number of them that connect in with parliament in a number of ways," he said.

"I'm aware that it was in the lead up to Christmas, there was a concern the meeting might be either then or two months later. There was an opportunity to meet and he did."

Labour MP Grant Robertson's challenged Revenue Minister Michael Woodhouse on the issue saying at the time the IRD had already initiated a review of foreign trusts.

"But only after the Prime Minister directed his close confidante to the Minister who's shut down the review. That's actually what happened isn't it."

To which Minister Michael Woodhouse said "absolutely not."

Swords clashed over the issue in Parliament this afternoon as Labour's Andrew Little said it smacks of cronyism.

"New Zealanders don't like it when people with connections to the Prime Minister get special treatment and denying this is just plain out of touch."

Key fired back saying: "The minister had dinner with the people who make Keytruda and then went out and advocated for it. Does that mean he's crooked?"

Keytruda is a melanoma drug that Labour said the taxpayer should be funding.

Mr Key told Parliament he simply did what would have been expected of him by making the referral.

"I have been completely straight and the member doesn't like because it doesn't suit his wild conspiracy theories. Well I'm sorry, yeah I am an available Prime Minister."

The release of the Panama Papers last month generated new scrutiny of the foreign trusts regime, and prompted a review of the disclosure rules for the secretive trusts.