Affair with MP brings down scandal-hit Australian treasurer

After tearfully apologising two years ago for conduct that included sniffing a female colleague's chair and pinging another's bra strap, the Treasurer of Western Australia might have been expected to stay out of trouble. He didn't, and yesterday Troy Buswell was forced to resign from the state government following revelations of an affair with a Greens MP, Adele Carles.

The man who controls the public purse in Australia's largest state had admitted using official funds during a series of rendezvous with Ms Carles. The affair, which began in late December and ended recently, came to light last weekend. Mr Buswell initially tried to brazen it out, calling a press conference on Monday at which he came clean and apologised to his wife, Margaret, his two sons, his Liberal Party colleagues, and his boss, the state premier, Colin Barnett.

Mr Buswell, 44, initially vowed that he would not resign, but at a meeting with Mr Barnett he was informed that his position had become untenable.

Quite apart from the political fallout, the pairing of the bombastic right-winger and the newly elected Greens MP has surprised many. Ms Carles, 41, who is married with three daughters, told a Sunday newspaper: "I could attempt to portray myself as the vulnerable one who was taken advantage of. However, this is simply not true. We made a mutual, albeit stupid, decision as two consenting adults."

It was the disclosure that Mr Buswell misused public funds that sealed his fate. He admitted charging a night's accommodation in the coastal town of Albany to his government credit card, and using his ministerial car on three occasions. He said he would pay back the expenses.

However, this is not the first time he has been caught out: last December, he admitted for the second time in two months that he had wrongly claimed a travel accommodation allowance. The previous scandal – which involved revelations that Mr Buswell had sniffed the chair of a female Liberal Party worker, drunkenly snapped the bra strap of a Labor Party worker and made sexist remarks to a Liberal MP – put him out of the running for the Liberal leadership. Margaret Buswell stood by her husband in 2008, declaring: "Troy's not corrupt. He's not an adulterer. He hasn't run off with anyone."

As well as the tryst in Albany, Mr Buswell and Ms Carles – the first Greens MP to be elected to an Australian lower house – spent two nights together in Sydney in March. However, he said he paid for that accommodation himself. Both politicians have insisted that the liaison did not compromise their parliamentary conduct, and Ms Carles has defended herself against Labor accusations of bias in supporting the government over controversial stop-and-search legislation. Mr Buswell said he was seeking "professional assistance".