NSW Labor leader Michael Daley says he is open to tinkering with his proposed luxury car tax if it unfairly costs farmers and workers.

The tax, which would increase stamp duty on vehicles over $100,000, has drawn criticism from regional workers who say their work utes, trucks and cars aren't a luxury.

"If there is some inherent unfairness in it, of course we are willing to sit down with people and remove that unfairness," Mr Daley told reporters in Kingscliff, on NSW's north coast, on Thursday.

"If we have to do something to exempt farmers from that, for working vehicles, we will."

Despite conceding he's willing to reconsider aspects of the proposed tax, Mr Daley doubled down on the fundamentals of the revenue-raising measure that Labor will use to pay for more nurses.

"If I have to increase the stamp duty to people who are millionaires, then so be it. I make no apology whatsoever for that," he said.

"If we want to have these new nurses, 5500 new nurses ... we need revenue."

But when quizzed on the intricacies of his new tax, which also applies to boats over $200,000, Mr Daley couldn't say whether it would apply to tractors, headers and other farming equipment.

He later confirmed the policy would not apply to them. He said he remains open to reconsidering "limited unforeseen consequences" of the tax.

The state opposition leader was on Thursday touring the battleground seats of Tweed, Lismore and Ballina, where tight contests could decide the outcome of the March 23 election.

Premier Gladys Berejiklian toured the region on Wednesday, where the coalition is fighting to hold on to both Tweed and Lismore while also trying to win back Ballina, which the Nationals lost to the Greens in 2015.

The premier met with farmers and tradespeople near Lismore who said the increase in stamp duty could cost them thousands of dollars for vehicles they relied upon for work.