John Howard has joined NSW Premier Gladys Berejiklian on the hustings in Penrith where polling suggests the Liberals are at risk of losing the seat to Labor.
NSW Labor continued to be hammered over its preference deals with the Shooters, Fishers and Farmers Party five days out from the state election while the coalition has been on the back foot over the cost of its election promises.
Former prime minister John Howard on Monday warned that the ALP's preference deal with the Shooters could lead to the state's strict gun laws being eroded.
Mr Howard joined Premier Gladys Berejiklian in the battleground western Sydney seat of Penrith ahead of Saturday's election.
The former federal Liberal leader said he stood by a statement he made before the Christchurch terror attacks about the consequences of preferencing the Shooters party.
"It's a statement I made before the tragedy across the ditch and it's a statement I repeat," Mr Howard told reporters.
"If Labor were to win with the help of the Shooters, the Shooters would demand a relaxation of our gun laws - that is as sure as night follows day."
NSW Shooters MP Robert Borsak accused the premier of politicising the New Zealand terrorist attack.
"How anyone could possibly believe that we would want to put the NSW public at risk with firearms policy beggars belief," he said in a video on Twitter.
"This coming from a premier whose party has made an art form out of dog whistling to racist white supremacists."
Labor leader Michael Daley reiterated he had no intention of watering down the state's gun laws, and accused the coalition of hypocrisy, given the government had relied on the Shooters to pass legislation.
"For the past eight years they (coalition) have relied on their (Shooters) votes in the upper house to get almost every piece of legislation through, including to make duck hunting easier and to make shooting in national parks legal," he said.
"People can want whatever they want but I'm telling you, if you want a change in gun laws, don't talk to Michael Daley. Talk to the hand because you won't be getting it."
Meanwhile, the parliamentary budget office on Monday released its impact statements for both the coalition and Labor.
The PBO found the coalition would have to borrow an extra $7.3 billion over four years to fund its election promises.
The budget would be $700 million worse off under a new Berejiklian government over the forward estimates, compared to the current projection, while the state would be $1.4 billion better off under Labor.