Two opinion polls published on Monday have Labor leading the Liberal-National coalition, ahead of an expected May 18 election.

Newspoll put the gap at 52-48 while Ipsos was 53-47.

The prime minister predicted voters would have "a bit more to say" about Labor in coming weeks, as they looked more closely at the opposition's policies.

"We've been the underdog in this campaign right from the outset," Mr Morrison told reporters during a factory visit on the Gold Coast.

"And what I know is Bill Shorten he has already measured up the curtains and for all I know he has probably gone out and bought the curtains, but my suggestion is he should keep the receipt."

Earlier, Mr Morrison said he was prepared to launch a negative campaign against his opponents.

"It's not a fear campaign, it's a truth campaign," he told 2GB radio.

Mr Morrison said Labor would slug Australians with an extra $200 billion worth of taxes, holding the economy back.

"When you do that, guess what? You run out of money for: hospitals, schools and in particular affordable medicines," he said.

"That's what happens with Labor - when they run out of their own money, they come after yours."

Labor deputy leader Tanya Plibersek said she was not taking anything for granted.

"What I'm going to focus on is convincing people - one-by-one if I have to - about the superiority of Labor's vision and also about the unity and discipline in our team," she told ABC Radio National.

Labor has accused the government of pushing back the election so the cash-strapped coalition can exploit an extra week of taxpayer-funded ads.

The coalition is spending more than $600,000 a day spruiking its policies.

"What you see from the government is a chaotic and divided opposition using taxpayers' own money to lie to them about investments in hospitals and schools," Ms Plibersek said.

"It's a dodgy ad man using taxpayers' funds to lie to taxpayers about what the government's doing."

The prime minister has dismissed the criticism, saying Labor did exactly the same thing when it was in office.

Labor leader Bill Shorten is also campaigning in Queensland on Monday.

Australian Associated Press