The facts emerged during Marshall's 15-minute court hearing for a mid-range drink-driving offence.

He pleaded guilty to being caught behind the wheel with a blood alcohol concentration of 0.112.

Marshall was fined $2000 and disqualified from driving for nine months. 

In court, defence solicitor Rod Watt said his client had been “sipping drinks” on the night of the offence, June 28, and had been suffering from a head cold. 

“There was no great intake of alcohol, though there was far more than he should have taken to drive,” Mr Watt told the court. “He was suffering from a head cold and thinks that probably may have affected his ability to judge how affected he was, nonetheless it is true that he had far too much to drink and then drove.” 

Marshall had been caught out by a random breath test. Mr Watt said his client had made no attempt to downplay the illegality of his behaviour and commended police in treating him “in the most cordial fashion”.

Marshall did not say anything during the hearing.

Magistrate Stafford said she was aware Marshall had been publicly chastised through recent media coverage for his behaviour and as part of his public standing, the offence had caused him to surrender two of his roles as temporary speaker of the Legislative Council and deputy chairman of the State and Regional Development Committee. 

Following his court appearance, Mr Marshall said the drink-driving case contributed to a driving record of which he was not proud.

He said the speeding fines were accrued in his younger days, with the most recent probably shortly after he was elected an MP.

“I made the mistake and I copped the punishment,” he said.