When WA Opposition Leader Mike Nahan returned from leave this week, his troops should still have been riding high after their recent surprise victory in the Darling Range by-election.

Instead the team was immediately put on the back foot as Dr Nahan bumbled his way through a media conference where he admitted he was still a dual citizen because of a long-running dispute with the US tax office.

As details of their leader's admission filtered through to his Liberal colleagues, many expressed surprise, frustration and disappointment.

Privately they lamented to reporters that they were not told earlier of the former WA Treasurer's tax issues.

They also bemoaned that, once again, he and his office's handling of an issue had further cemented the widespread belief that Dr Nahan was the gift that keeps on giving to the Government.

A Government on the ropes

During his absence, the Opposition had the Government on the ropes.

Bad tourism figures were released, another senior tourism bureaucrat was on the way out and a riot at Greenough Prison had left a red-faced Government facing WA's biggest prisoner breakout in living memory.

The Prison Officers' Union has blamed understaffing and overcrowding for the Greenough riot. ( Supplied: WA Police )

The Opposition had been doing its job — focusing on the task of holding the Government to account.

So a sudden change in political fortunes, as Dr Nahan admitted he was embroiled in a tax stoush with the US Government over a "sizeable sum" of money, was music to the Government's ears.

It also provided a welcome distraction from the Government's own dual citizenship problem — an admission by Corrective Services Minister Fran Logan that he had used his UK passport to "get past the queues and get straight into the EU" on a recent overseas trip.

Fran Logan has a UK passport. ( ABC News: Jacob Kagi )

Mr Logan's admission came at a time when academics back home in Western Australia had been raising questions about whether renewing or using a foreign passport could render an MP ineligible to sit in the WA Parliament under a little-known clause of the WA Constitution.

Treasurer Ben Wyatt didn't waste any time seizing on the political opportunity created by Dr Nahan, and he happily helped let the matter distract attention from the Government's own woes.

"It is a curious, odd thing to have a political leader with this (tax) issue, it's very unusual," Mr Wyatt said.

A growing list of Nahan gaffes

For Dr Nahan's colleagues, it was just the latest in a series of bungles since he took over the leadership after the Liberals' devastating state election loss.

His growing list of gaffes, according to colleagues, includes dithering on the proposed gold royalty hike, and getting their Nationals colleagues offside by calling for the Royalties for Regions program to effectively be scrapped.

While no Liberals were this week talking about knifing Dr Nahan, most agreed his handling of the citizenship and tax dispute issues was yet another nail in his leadership coffin.

It is unclear exactly how much money the IRS is pursuing Dr Nahan for. ( Reuters: Jose Luis Gonzalez )

The timing could not have been worse, with all Liberal MPs meeting for their annual "love in" this week.

The meeting no doubt provided the opportunity for their private concerns about his latest revelations to be a source of further political whispering.

Attack of the 'white ants'

Dr Nahan cut a lonely and somewhat dejected figure as he arrived ahead of the meeting.

Clearly aware of the ongoing rumblings over his leadership, Dr Nahan's apparent frustration with those colleagues who are working against him appeared to spill out in a very public way.

He told the waiting ABC reporters he wanted those colleagues not on board to start acting like team players, "rather than sitting back and being a white ant".

"There are some people who have lost the plot and that will be an issue for discussion," Dr Nahan said.

"There are a few people who are struggling to be part of a team and I'm an old football player and it's very simple — if you're not a team you can't win it.

"I haven't allowed their white-anting to undermine me or take my eye off the game."

Later in the day Dr Nahan emerged to declare it a "positive meeting", where he had secured an "iron-clad uniform commitment" from colleagues that they backed him as leader.

Zak Kirkup and Alyssa Hayden said Mike Nahan enjoys their full support. ( ABC News: Eliza Laschon )

He also reaffirmed he intends to lead the party to the next election in 2021.

"The issue of the leadership, it's all about the numbers, politics is about numbers, and I can assure you that if there were a vote I'd have overwhelming support.

"So the leadership is actually not an issue," Dr Nahan declared.

The elephant remains in the room

It may be true that Dr Nahan still enjoys the numbers, but even his most loyal colleagues know that his leadership will remain the elephant in the room for the foreseeable future.

Dr Nahan took on the role of Opposition Leader immediately after the Liberals were turfed out of office after eight-and-a-half years, and when no one else showed any interest in doing what most consider the toughest job in politics.

While some of his colleagues may have an interest in the job in the longer term, no one seems keen for a tilt any time soon, because the next state poll is still three long years away.

Dr Nahan's stumbled messages this week about his citizenship and tax dispute have raised further concerns about his leadership and only reinforced with some colleagues that he is not the person to lead them to the next election.

But in the absence of an obvious challenger, you might forgive Dr Nahan for publicly calling out the "white ants" who clearly don't have the support, inclination or guts to mount a challenge.