Australia's only Liberal premier Jeremy Rockliff will face a no-confidence motion when he returns to parliament for the first time since his long-serving colleague and attorney-general quit.
Tasmania's minority government copped another blow earlier this month when Elise Archer resigned after being sacked from cabinet over workplace bullying allegations and leaked texts.
The state's Labor opposition on Tuesday confirmed it would move a no-confidence motion in Mr Rockliff when parliament resumes on October 17.
The Liberals have faced a knife-edge situation in parliament since May when Lara Alexander and John Tucker moved to the cross bench and plunged the government into minority.
A spokeswoman for the pair said they planned to honour a signed commitment to provide votes of supply and confidence to the government, meaning Mr Rockliff has the numbers to defeat a no-confidence motion.
However, both criticised Mr Rockliff's leadership last week, with Mr Tucker labelling him a "lame duck".
The Liberals return to parliament with just 10 of 25 lower house seats.
A recount to find a replacement for Ms Archer, likely to be won by a Liberal, won't begin until October 23.
Labor have given the government a "pair" in the meantime, meaning one of their eight members - not including half-Labor-half-independent David O'Byrne - will abstain from votes.
There are two Greens MPs as well as one other independent.
Labor MP Josh Willie said the premier was presiding over one of the most unstable governments in recent memory.
"This is a government that is fighting amongst itself and not focussing on the issues Tasmanians care about," he told reporters.
Liberal MP Felix Ellis described the no-confidence motion, several of which have failed since the government has been in minority, as a stunt.
Ms Archer was sacked from cabinet on September 29 but then walked back an initial resignation announcement because of community support.
Mr Rockliff last Wednesday told her to either resign or guarantee a vote of supply and confidence as an independent by Monday or he would call a snap election.
Ms Archer, who was elected to parliament in 2010, resigned a few hours later.
She launched a scathing attack on the premier for not affording her due process.
Ms Archer also denied the bullying allegations and said a leaked message where she said she was "sick" of abuse victim-survivors was taken out of context.
