The Liberals, who were re-elected in March, are working to finalise a revised confidence and supply agreement with two cross bench MPs who were dumped from the Jacqui Lambie Network.
Miriam Beswick and Rebekah Pentland will sit as independents after being given their marching orders on Saturday by Senator Lambie for being too "cosy" with the Liberals.
The pair have both guaranteed continued support for the Liberals, who hold just 14 of 35 seats in Tasmania's lower house.
Senator Lambie accused the pair of failing to hold Infrastructure Minister Michael Ferguson to account over delays for two new Spirit of Tasmania vessels.
It was revealed the larger ships, slated to begin arriving in late 2024, won't be able to operate at full capacity for about a year because an upgraded wharf won't be ready.
Mr Ferguson, also the deputy premier, on Monday resigned from the infrastructure portfolio, apologised and took a shot at government-owned Spirit of Tasmania operator TT-Line.
"In the absence of the company owning up to this profoundly disappointing situation, as the (minister), I will," he said.
"The ongoing commentary concerning the project is proving an unnecessary distraction."
Mr Ferguson said he could not afford the government to be distracted ahead of preparations for the 2024/25 budget, to be delivered on September 12.
Senator Lambie welcomed Mr Ferguson's decision to step aside and also called for him to resign as treasurer.
"All ministers have a responsibility to the people of Tasmania to carry out their duties to the highest standard," she said.
"Where that obligation can't be met, they must be moved on.
"Unfortunately, Mr Ferguson proved to be incompetent. He has a very odd view of what it means to be upfront and honest with the Tasmanian people."
The ships have been substantially delayed and TT-Line in June provided details of an extra $81 million paid to the Finnish builder to keep the project on track.
The new ships also need a temporary yet-to-costed berth to be built.
In mid-August, TT-Line chair Michael Grainger pledged to "set the record straight" about the reasons for delays before being sacked by the government.
Premier Jeremy Rockliff will assume infrastructure responsibilities and noted a desire to end the "distraction" of the port challenges.
Labor Opposition Leader Dean Winter criticised the political instability under Mr Rockliff.
Opposition Leader Dean Winter says Mr Rockliff's government is unstable. (Ethan James/AAP PHOTOS)
The Liberals went to an early election in March after falling into minority when two MPs quit the party.
"Jeremy is a nice guy, but this is getting ridiculous," Mr Winter said on Sunday.
"The Liberal-Lambie coalition is already in tatters four months after it was formed."
The Jacqui Lambie Network's third Tasmanian MP Andrew Jenner remains with the party.
10°C