NSW political leaders will go toe-to-toe in a bid to win over undecided voters in the final debate of the election campaign.

Premier Dominic Perrottet and Labor leader Chris Minns have run disciplined campaigns and will be looking to expose any weakness in their counterpart’s policies when they face off in the debate on Wednesday night.

With just three days left to gain traction before polling day, the debate will allow 100 undecided voters to put questions to the leaders about their vision for the state.

It will be broadcast on Sky News live from Penrith in western Sydney, where both parties are locked in a do-or-die battle for key seats likely to decide the election.

Cost of living and economic management issues are likely to dominate as Mr Perrottet and Mr Minns seek to convince voters their fiscal plans are sound.

Each accused the other of “black holes” after an analysis of their costings on the budget bottom line was released by the Parliamentary Budget Office earlier in the week.

Governance Institute of Australia chief executive Megan Motto urged voters to consider the ethical actions and the integrity of candidates .

“Good governance and an understanding of ethics and integrity from our leaders should set the bar for organisations across the nation, leading from the top to influence the public and private sectors and the institutions we rely on,” Ms Motto said.

Meanwhile, Labor is promising to end the secrecy around privatised toll roads in NSW by tabling in parliament details of the toll contracts over the past 12 years.

Labor’s roads spokesman John Graham says toll costs were too high and a Labor government would cap them at $60 per week.

“We don’t accept that toll costs are a state secret,” he said.

Labor has also committed $14 million over the next four years to hire 100 additional National Park staff, to deal with weeds and pests.

“After more than a decade of neglect, pests and weeds have exploded in our national parks, we need more boots on the ground to address this,” Labor’s environment spokeswoman Penny Sharpe told AAP.

“These will be good, secure, local jobs where workers can build a career in these protected landscapes to tackle threats like weeds and pests.”

– AAP