Tasmanian Labor leader Rebecca White has suggested it might be worth considering a "bonking ban" for the state's parliamentarians, in the wake of Primary Industries Minister Sarah Courtney's decision to stand down after revealing she was having a relationship with the head of the department she controlled.

Key points: Primary Industries Minister stood down after declaring her relationship with her department head

Primary Industries Minister stood down after declaring her relationship with her department head Opposition Leader Bec White says a "bonking ban" may be needed for parliamentarians

Opposition Leader Bec White says a "bonking ban" may be needed for parliamentarians Greens leader Cassy O'Connor says there are "legitimate questions" over potential conflicts of interest

With Ms Courtney sitting behind him, Premier Will Hodgman told Parliament on Tuesday she had stepped down after declaring that she had started a "personal relationship" with her department head John Whittington.

While Ms Courtney will face a code of conduct investigation, the Liberals face the prospect of their slender hold on government coming under increased pressure just eight months after being elected.

Ms White addressed probity concerns, saying there needed to be a prompt inquiry into Ms Courtney's possible conflicts of interest.

But when an ABC journalist asked if a so-called "bonking ban" — similar to that which was implemented by former prime minister Malcolm Turnbull following Barnaby Joyce's affair with a staffer — might be on the cards for Tasmania, Ms White laughed.

"I don't think Tasmania has ever had to consider whether Parliament should enforce a bonking ban, but given what's occurred today I think it has to be considered," Ms White said.

Ms White said the code of conduct probe faced by Liberal minister Michael Ferguson over his involvement in the June dismissal of Cricket Australia employee Angela Williamson was finalised "overnight", adding she expected the Courtney investigation would similarly be conducted "swiftly".

Ms White declined to nominate examples of decisions made by Ms Courtney as minister which could be compromised in light of her relationship with Mr Whittington, instead saying the "investigation, I presume, will find out the answers to all those questions".

Both Sarah Courtney and John Wittington have stood down from their positions. ( Facebook/IMAS )

Courtney's decisions brought into question

Tasmanian Greens leader Cassy O'Connor said her party would demand answers over "how long has this been happening and has there been a potential conflict of interest".

"I'm reluctant to go into the question of the relationship, in the context of the potential misuse of power, for example, or conflict of interest," said Ms O'Connor.

"The question is what decisions made by the Minister on the basis of advice are now brought into question and whether stakeholders can have any confidence in those decisions in the context of this relationship.

"Ms Courtney has only been a minister for six months and this is a spectacular and awful fall from grace," Ms O'Connor said.

"We recognise the Premier has asked his head of agency Jenny Gale to undertake a code of conduct investigation and Damian Bugg QC to do the same for the public servant involved."

Ms O'Connor flagged the Greens would be asking the "legitimate questions" over conflict of interest and would be "pursuing them in Parliament this week".

Ministerial code of conduct

Premier Will Hodgman said the March 2018 announcement of a code of conduct for ministers was a commitment by his Government "to act with integrity and propriety for the people of Tasmania".

It came after a 2011 Integrity Commission report found a number of shortcomings in relation to the standards expected of Tasmanian government ministers, with some "not subject" to any code at all.

While the 2018 document states ministers are "expected to behave according to the highest ethical standards in the performance of their duties as they hold a position of trust, and have a great deal of discretionary power which can have a significant impact on citizens of Tasmania", it does not explicitly mention personal relationships between ministers and others, other than to say ministers are to "treat everyone with respect, courtesy and in a fair and equitable manner without harassment, victimisation or discrimination".

In 2017, Labor and the Greens were singled out by the Liberals for doing "nothing to advance the single code of conduct" while they were in coalition government between 2010 and 2014.

Leading the attack then was Will Hodgman's Parliamentary Secretary, Sarah Courtney.