Tensions have boiled over after an MP from Pauline Hanson's One Nation party in Western Australia quit and engaged in a bitter Twitter exchange with his former colleague in the days after his defection.

Key points: Charles Smith is an independent in the WA Parliament after last week quitting One Nation

Charles Smith is an independent in the WA Parliament after last week quitting One Nation A public spat between Mr Smith and his former colleague ensued in the days that followed

A public spat between Mr Smith and his former colleague ensued in the days that followed His resignation follows a lengthy period of tension among WA's One Nation team

Last week East Metropolitan MP Charles Smith announced his decision to quit One Nation amid what he described as his "frustration" with the party and its WA leader, Colin Tincknell.

Loading

In the days that followed his resignation from One Nation, Mr Smith became embroiled in a bitter back and forth with staffer and former party candidate Rod Caddies.

Mr Caddies ran for One Nation in both the 2017 state election and 2018 Darling Range by-election.

He also serves as a staffer to Mr Tincknell.

"You really are quite the bitter and twisted little man," Mr Smith posted on Twitter, in response to a tweet from Mr Caddies.

"Eaten up with jealousy and rage because you were NOT elected … You are a disgrace and a liar," he said.

Mr Smith continued to attack Mr Caddies, referring to him as a "semi-literate goon".

"You really are the septic pustule on the anus of vulgar society," he posted.

Mr Caddies responded by mocking Mr Smith's claim that nobody liked him or Mr Tincknell, while also saying the now-independent Upper House MP had anger issues.

Smith accused of acting 'child-like'

Loading

Mr Tincknell also laid into Mr Smith in an interview posted on Facebook over the weekend, saying his former colleague was "not a team player".

"He is child-like in the way he acts," Mr Tincknell said.

"Obviously he has got to blame someone … he likes to blame someone for his own shortcomings.

"He wanted to go his own way, well now he has the opportunity to do that."

Mr Smith's resignation followed a lengthy period of tension among WA's One Nation team, which has been present since the 2017 election in which three of the party's MPs were elected to the Upper House.

Of the eight West Australians to serve in state or federal parliament under the One Nation banner, five left the party before their terms expired.

Former party candidate Rod Caddies says Mr Smith has anger issues. ( ABC News: Jessica Strutt )

As well as Mr Smith, One Nation's three MPs elected to the WA Parliament in 2001 quit the party, while Rod Culleton did the same before he was deemed ineligible to sit in the Senate.

Of the other three, Mr Tincknell and Robin Scott are still One Nation MPs in WA, while Peter Georgiou failed in his Senate re-election bid.