Former West Australian Treasurer Troy Buswell has declined to comment on claims he was drunk when he crashed his car several times on the short journey home from a wedding.

Mr Buswell quit cabinet after revelations he had a mental breakdown after crashing into the front gate of his Subiaco home in Perth’s inner west while returning from the reception in the early hours of February 23.

It later emerged he also smashed into four parked cars and a telephone pole.

He was last week fined $3100 and disqualified from driving for one year over 11 traffic offences committed on the journey.

Mr Buswell, who remains the MP for Vasse, told reporters before his return to parliament on Tuesday that he had admitted to careless driving, failing to report an accident and failing to stop after an accident.

“I have accepted the consequences of my action in relation to those matters,” he said.

But he would not comment when repeatedly asked whether or not he was drunk that night.

A witness told police he had seen Mr Buswell barely able to stand as he entered his property.

The MP wasn’t questioned by officers on the night or later charged with drink driving.

Mr Buswell said he condemned drink driving.

“Police have investigated those matters … I’m not a police officer and I’m not a lawyer from whom they would have received advice,” he said.

“In my view, the matter has been dealt with.”

He was also asked repeatedly if he would personally pay for repairs to the cars that had been damaged, saving the government insurer Risk Cover from having to use taxpayer funds.

He said he was awaiting the outcome of the insurer’s assessment.

He said he was “embarrassed and mortified” by the incident.

He had been diagnosed with bipolar depression – a condition his doctor believed he has suffered from for some time – and returning to work was a big part of his treatment, he said.

He would not comment on whether abstaining from alcohol was part of that treatment.

“It’s hard. It involves a lot of hard work and it involves a lot of support, and it’s going to be ongoing for an extended period of time.

“Now, does that mean that I’m incapable of doing my job? No.

“Should it mean that anybody who has suffered this type of illness be rendered incapable of doing their job? No.

“And I hope people who do face the sorts of challenges that I’ve had to face, get help.”

Mr Buswell said he was unsure if the crashes had triggered the breakdown.

“I don’t know the answer,” he said.

But he admitted he still would not have been fit to hand down the state budget on Thursday as would have been the case had the dramatic events not unfolded.

Mr Buswell spent eight nights in hospital receiving treatment after the crashes, with his now-former chief of staff Rachael Turnseck not telling anyone about them.

She eventually advised Premier Colin Barnett that Mr Buswell had suffered a breakdown but other MPs were told he was simply unwell.

Those facts have been pounced on by the opposition, which claims a cover-up.

Mr Buswell declined to specifically comment on the claim.

“It was very, very difficult. I was simply trying to get some stability back and try and grasp what was happening to me.”

Asked whether he would serve his full term, Mr Buswell said his “report card will read cautiously optimistic”.