Prime Minister Scott Morrison has cancelled plans to visit Papua New Guinea's Prime Minister next week.

James Marape came to power in May last year but there has been growing unrest in his coalition.

Several Government MPs, including Deputy Prime Minister Sam Basil, on Friday crossed the floor to join the Opposition, which voted to suspend Parliament.

Foreign Affairs Minister Patrick Pruaitch and Attorney-General David Steven also abandoned the Government.

Mr Morrison said on Friday he still intends to travel to Papua New Guinea, but a spokesperson for Mr Morrison said Mr Marape has since contacted him and asked him to defer his visit.

Mr Marape said he was confident he would regain the numbers needed to hold onto the nation's top job, despite the pressure to resign.

"Numbers shifting and numbers jostling … in the next 14 [to] 17 days sanity will prevail and the numbers we have will build up to over 56 and for us to win government."

But Opposition Leader Belden Namah told a press conference at a hotel in Port Moresby there were 61 MPs in his camp.

"As far as the numbers are concerned, the new government is here in the Crown Hotel," he said.

The two groups will now go into political camps, ahead of parliament returning in December, when a vote on a new leader would be possible.