Christian Porter took a calculated risk when he quit as Western Australia's Treasurer to pursue a career in federal politics and he's not hedging his bets now.

Key points: Christian Porter was a high-flying WA MP before moving to federal politics

Christian Porter was a high-flying WA MP before moving to federal politics His safe seat of Pearce has become increasingly marginal in recent years

His safe seat of Pearce has become increasingly marginal in recent years The ALP, unions and GetUp have spent large amounts trying to unseat him

He says there is no plan B if this Saturday's election does not go his way.

"That whole exercise [of leaving state politics] was very heavy with risks of a whole range of types," Mr Porter said.

"It had occurred to me that federal politics is often very tough, particularly with very large seats, particularly with boundaries being re-drawn, so anyone who didn't want to have personal political risk would not have done that."

Mr Porter was poised to become Western Australia's next Liberal Premier, but decided his ambitions went beyond merely leading the state.

He also correctly picked the changing political winds, quitting state politics on a high in 2012 before then premier Colin Barnett's popularity took a turn, leading to a thumping election loss in 2017.

From safe to marginal in six years

Mr Porter jumped onto the federal stage in the 2013 election that swept the Abbott government to power as the member for Pearce, back when it was considered an unlosable seat for the Liberals.

He set about quickly rising in seniority within the Coalition, entering Cabinet in 2015 as social services minister before being promoted to Attorney-General.

But Mr Porter might have underestimated how much Pearce would become a problem for him just two elections later.

A 5.6 per cent swing against him in 2013 converted his safe seat into a marginal one, which he now holds by just 3.6 per cent.

Space to play or pause, M to mute, left and right arrows to seek, up and down arrows for volume. Watch Duration: 3 minutes 18 seconds 3 m 18 s Shifting demographics are transforming the seat of Pearce into a marginal electorate

"He [Mr Porter] has found himself in an electorate that is changing," political analyst William Bowe said.

"[Pearce] is exactly where urban development has been at its most prolific and that is really changing the complexion of the electorate.

"What was once a kind-of semi-rural seat and quite safe for the conservatives is now your classic outer-suburban marginal seat.

"The question is how much further does [Mr Porter's] political career take him in the future?

"For the time being, he has got this big obstacle that he needs to hold his seat."

Attorney-General Christian Porter is locked in a battle to retain his northern Perth seat of Pearce. ( AAP: Mick Tsikas )

Focus only on retaining seat

Mr Porter has declared himself the underdog in the fight for Pearce but has no contingency plan if he loses the seat.

"That is a future me's problem," he said.

"Any second that I spend thinking about what might happen if I lose is a second I'm not spending trying to win."

Regardless of the outcome on Saturday, a loss might not spell the end of Mr Porter's political career.

"He wouldn't be the first person to lose a seat and then seek to make a comeback, whether in that seat or another seat in future," Mr Bowe said.

"If he does lose the seat I would be very surprised if that was the last we've heard of Christian Porter."

Political analyst Peter Kennedy said Mr Porter's ambition could take him all the way to The Lodge.

"If he survives on Saturday night, there is no doubt that he will be considered for higher duties in the Liberal party," he said.

"It will take time. He is only 48. But if all the stars align it just could be possible that he could end up in the top job."

Christian Porter (left) is being touted by some as a possible future prime minister. ( ABC News: Ian Cutmore )

Mr Porter said it was "very generous" for anyone to consider him future leadership material.

"But you can't do anything in politics unless you first win your seat and you do not achieve anything in politics unless you are part of a team.

"I have no particular ambitions to [become Prime Minister]. What I want to do is win my seat."

The Liberals' next big things

Mr Porter is among several high-profile Liberals viewed as the next generation of leaders who the party is desperate to see hang on come Saturday.

"I think that could be a theme of the election," Mr Bowe said.

"If it does go very badly for the Liberals and they are reduced to a core of safe seats, then they are going to have a clear out of members of seats which are not the safest, who tend to be the younger, rising stars of the party.

"And that is the kind of face that they need to present to the public going forward."

Canning MP Andrew Hastie is one such "rising star" the Liberals — particularly the conservative side of the party — want to see win.

While his seat appears much safer than Mr Porter's, with a margin of 6.8 per cent in an electorate with a high proportion of retirees, Prime Minister Scott Morrison's presence in Canning during the election campaign shows the Liberals do not want to take any chances.

"Undoubtedly he is a rising star of the conservative end of the Liberal Party," Mr Bowe said.

"There is a point of view that the conservative end of the party has been too assertive in recent years with the Peter Dutton leadership challenge.

Liberal MP Andrew Hastie is seen as a future leader among conservative Liberals. ( Jed Cooper )

"Nonetheless he is a candidate with a military background, [who] is not a politician from central casting, and he plays well with voters in his electorate where there are a lot of older voters.

"Unquestionably he is a fresh face for the Liberal party and it would be a loss for them if he was to lose that seat."

Star performers 'targeted'

Mr Porter said the party's star performers were being targeted by outside groups, which added further challenges into an already challenging campaign.

"There is no doubt that GetUp and the Australian trade union movement have singled out a number of people inside the Liberal Party that they want to basically knock off," he said.

Sorry, this audio has expired WA a key battleground in final days of election campaign

"And I think they want to knock those people off because they represent significant contributors to Liberal politics and the way our team operates.

"In my electorate … we'll have — between Labor, the unions and GetUp — in excess of $1 million spent to try and unseat me.

"And yes, there are other members around the country — Greg Hunt, Andrew Hastie — who are significant contributors to Liberal politics, that they are trying to pick off one by one."