Pauline Hanson's One Nation party has been hit by another MP defection, with one of its three West Australian parliamentarians quitting to sit as an independent.

Key points: Charles Smith was elected in 2017 alongside two other One Nation candidates

Charles Smith was elected in 2017 alongside two other One Nation candidates Mr Smith is the fourth West Australian One Nation MP to quit the party

Mr Smith is the fourth West Australian One Nation MP to quit the party His resignation will weaken the party's influence in WA's Parliament

The Upper House of WA's Parliament was told on Tuesday night first-term East Metropolitan MP Charles Smith would quit the party amid what he said was his "frustration" with One Nation.

He made a brief statement announcing his decision in Parliament.

"Today is the end of a long line of frustrations for me and, Madam President, I advise the house that I have resigned from One Nation and I stand as an independent member," Mr Smith said.

Current and former One Nation members (l-r) Peter Georgio, Senator Brian Burston, Senator Pauline Hanson, Robin Scott MLC, Charles Smith MLC and Colin Tincknell MLC. ( Facebook: Charles Smith )

In later a statement, Mr Smith said he had not made the decision lightly but laid the blame for his move at the feet of WA One Nation leader Colin Tincknell.

"I was elected to represent the people of the East Metro region, which I have done, but I feel suffocated by a complete lack of leadership and direction from the party leader, Mr Tincknell," he said.

"It seems that Queensland just wanted bums on seats in WA. We receive no communication whatsoever and none from Mr Tincknell.

"We usually don't know the 'party direction' until we meet on the morning that Parliament sits."

He said promises to improve the party had come to nothing.

"Nobody knows what is going on. It is not hard to send an email stating what position will be taken on each issue, yet that doesn't happen," he said.

"In countless meetings this has been addressed with a promise to improve, to no avail."

Mr Tincknell and One Nation national leader Ms Hanson have been contacted for comment.

Latest in a line of defections

Mr Smith is the fourth of six One Nation members elected to the WA Parliament to quit the party, with all three of those elected in 2001 defecting before their terms expired in 2005.

In Federal Parliament, members Brian Burston, Fraser Anning and Rod Culleton all left the party after their election.

Relations between Mr Smith and Mr Tincknell are understood to have been strained for some time.

Mr Smith was elected with Mr Tincknell and Robin Scott amid a surge in One Nation support at the 2017 state election.

Charles Smith, pictured far right, along with (from left) One Nation's Robin Scott and Colin Tincknell, and Rick Mazza from the Shooters, Fishers and Farmers Party. ( ABC News: Jacob Kagi )

That gave the party a powerful crossbench position in WA's Legislative Council, holding three of the 36 spots in the chamber.

Mr Smith's resignation would dilute that influence significantly.

Defection a headache for Labor Government

The Government needs the support of the Greens and at least one other member to get legislation through the Upper House.

Political analyst Peter Kennedy said Mr Smith's decision would complicate the McGowan Government's ability to negotiate with the crossbench.

"Having an extra independent in the Upper House makes it a little bit for difficult for the Government to get its legislation through," Mr Kennedy said.

Pauline Hanson has had ongoing problems maintaining party discipline. ( ABC News: Andrew O'Connor )

"Previously they just had to negotiate with One Nation, and once they reached an agreement there would have been three votes there.

"Now negotiating with One Nation, there's only two votes there, and they'll have to negotiate as well with the new independent."

Mr Kennedy said the party had made a habit of defections in the Upper House.

"The problem for One Nation has been party discipline," Mr Kennedy said.

"A lot of people are attracted to new parties and small parties because they don't have the rigid format of the major parties — the Liberals and Labor.

"But in the end, the reality is that the party discipline is important and small parties can't be effective unless they do have that party discipline, and some of the members find that very difficult."