Former prime minister John Howard believes Scott Morrison has gained ground two weeks into the federal election campaign with a "very effective" performance.
Mr Howard on Tuesday joined the Liberal candidate for the marginal seat of Reid, child psychologist Fiona Martin, for a street walk through Burwood in Sydney's inner west.
The seat had been held by Malcolm Turnbull supporter and former minister Craig Laundy, who stole it from Labor in 2013 but is retiring.
Mr Howard said Mr Morrison had shown "tremendous energy" and had campaigned "very, very effectively" since calling the poll on April 11.
"Any marginal seat is critical because my judgement is that in the first stages of the campaign Scott Morrison has gained ground," Mr Howard told reporters.
"I think he's campaigned very well."
The former Liberal leader said his presence in the electorate was a "common sense decision".
"My attitude is, I'll do anything I reasonably can to help Scott Morrison get re-elected as prime minister of Australia," Mr Howard said.
The 69-year-old was given a rock-star greeting by many locals during his walk along Burwood's main shopping strip and into Westfield.
Mr Howard could barely walk a metre inside the centre without being stopped for a handshake or a selfie.
People jostled to get photos with Mr Howard, leant out of truck windows to pump their fist at him and even the Labor candidate for Reid, Sam Crosby, stopped to shake his hand.
Flanked by a pack of blue Liberal shirts, the former PM introduced locals to Ms Martin, describing her as "the future" - even though he had not met her before Tuesday.
Despite a largely positive response, one woman stopped Mr Howard to call him a war criminal and claim he does not understand multiculturalism.
"You will lose this election ... because of our non-English speaking people," she said.
Liberal Party volunteer Charles said Mr Howard's appearance was "of course" an indication of concern that Reid could become a Labor seat.
The Liberals hold Reid on a margin of 4.7 per cent.
"We are very, very, very on the edge," the 72-year-old told AAP.
"For Craig (Laundy) to leave us like that, he made a hole, and Fiona has a very hard task in a very short period of time and we cannot blame her in any way, because she is doing an extremely good job," he said.
Australian Associated Press
