Scott Morrison is facing two more potential resignations from his senior team weeks out from the federal election, amid speculation Christopher Pyne and Steve Ciobo are planning to retire.

The prime minister has already lost frontbenchers Kelly O'Dwyer, Michael Keenan and Nigel Scullion, who will retire from parliament at the May poll.

Mr Ciobo, the defence industry minister and an 18-year parliamentary veteran, tweeted on Friday he was looking forward to travelling to Indonesia within days to sign a landmark free trade agreement.

AAP

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But The Sydney Morning Herald reported on Friday the Liberal National Party MP is ready to quit.

The Queenslander was demoted from the trade portfolio after the August leadership spill when he ran for deputy.

A Queensland Liberal source told AAP he would be "surprised" if Mr Ciobo retired from parliament as he was currently very active in fundraising for the election campaign.

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South Australian Senator Simon Birmingham was asked on Friday if he expected any other frontbench colleagues to resign and he replied: "No."

"I say to Australians: If the ministers in the government are giving up on the government, you should too" - Opposition Leader @billshortenmp #auspol @SBSNews pic.twitter.com/b5cUZRiOwa — Brett Mason (@BrettMasonNews) March 1, 2019

Mr Pyne recently revealed how hard he took last year's spill and said he did not expect he could ever lead the Liberal Party.

Labor leader Bill Shorten said the resignation speculation showed the government had given up.

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"I think cabinet ministers retiring on the eve of an election shows that this is a government that has given up," he told reporters in Sydney.

"I say to Australians, if the ministers in the government are giving up on the government, you should too."