PNG's former prime minister Sir Mekere Morauta on Tuesday accused Mr Turnbull of interfering in the domestic politics of Australia's neighbour barely two weeks before the country's caretaker period begins.
Mr Turnbull has not travelled to PNG since taking over the top job in 2015 and Mr Morauta said the government in Port Moresby would"spin"a visit so close to the election as an endorsement of Prime Minister Peter O'Neill.
"That is a very dangerous position for the Australian Prime Minister to put himself in,especially with the prospect of a new Government just around the corner,"Mr Morauta said.
Mr O'Neill - who struck a deal with Australia to host the Manus Island detention centre for asylum seekers - has faced persistent claims of corruption while PNG's economy has struggled.
and Mr O'Neill later.
"Mr O'Neill will use this visit to prop up his sagging image and boast to Papua New Guineans that he commands Australia's support,"Mr Morauta said.
Writs for elections are expected to be issued on April 20,with national ballot considered mostly likely to be held over two weeks in July.
Australia has relied on PNG,along with Nauru,as part of the so-called"Pacific solution"for offshore processing refugee claims.
The supreme court in PNG last year,but despite Mr O'Neill pledging to close the centre more than 800 asylum seekers remain on the island,with hopes a deal with the US will see some of the men resettled.
Mr Turnbull will also need to navigate to fund local hospitals and education.
International Development Minister Concetta Fierravanti-Wells has and said the government would not honour the request.
Mr Morauta,a former governor of PNG's reserve bank who stepped down from politics in 2012,has been a fierce critic of Mr O'Neill in recent years and.
He said the two leaders had met in Australia recently and at several international summits.
"What is so important that Mr Turnbull should be visiting now? What is so important that it cannot be conveyed to the incoming Government in a couple of months'time?"Mr Morauta said.
"If Mr O'Neill happens to be the Prime Minister after the election,fine,visit him then. We would all accept that. But to visit now is inappropriate,"he said.
Both Mr Turnbull and Mr O'Neill have been asked for comment.