Prime Minister Julia Gillard could be forced out of office based on her previous links to the alleged wrongdoing committed by New South Wales MP Craig Thomson.

Allegations have emerged that Gillard may have played a key role on the way Fair Work Australia has been handling its probe on Thomson, who is facing accusations that he illegally tapped funds belonging to the Health Services Union.

Thomson served as HSU's national secretary while Gillard was the head of the Workplace Relations Ministry.

The Coalition has suggested that Gillard had made contacts with FWA officials while the embattled Thomson was under investigation though the nature of the communication was still under wraps.

Coalition frontbencher Christopher Pyne said Tuesday that the true nature of Gillard's actions towards the Thomson issue must be revealed.

Pyne added that his colleagues in the Parliament and for sure, the Australian public, have been mighty curious on why it is taking FWA so long to complete its inquiry on Thomson.

He reminded that it has been three years since the Labor MP was placed under investigation.

"And Julia Gillard has a lot of questions to answer," Pyne told ABC while stressing that speculations now abound on the matter.

The Thomson issue has been a thorn on Gillard's side as she will likely lose a key ally if the legislator is found guilty and forced to relinquish his Parliament seat.

Most likely too, the controversy would make it difficult for the Labor-led government to search for a viable replacement for Thomson that can assume for the NSW seat that he would vacate.

More so, HSU officials believe that in the event Thomson would emerge as guilty once the FWA has wrapped up its probe, a move could be set in motion for the Prime Minister to be ousted.

Present HSU national secretary Kathy Jackson believes Thomson's misconduct would constitute a prime example of grave mistake for Gillard, especially now that her previous actions have been linked to the scandal.

On that basis alone, the Coalition needs to convince Independent MP Andrew Wilkie to support a 'no-confidence vote' against the Prime Minister as he had pledged when he severed his ties with the Labor government over the weekend.

The Coalition is still vague on such possibility but Pyne allowed that the Thomson case can indeed be regarded as a form of serious misconduct for the Labor government.

He added, however, that the Coalition will only employ such move in "the most serious of circumstances."

On her part, Jackson is firmly convinced that the Thomson case is a good reason for Wilkie to support any move that would replace the current government.

Jackson also insisted that prior to the completion of its probe, the FWA must give definitive explanations on why they required such long period to investigate the allegations against Thomson.

The FWA owes it to HSU members to shed light on the matter, Jackson stressed.