Fair Work Commission (FWC) vice-president Michael Lawler has resigned, ending a long-running legal dispute and leaving a big bill for time on leave.

Employment Minister Michaelia Cash made the announcement on Thursday.

“Shortly before Question Time, I received notice from the office of the official secretary to the Governor-General, indicating that His Excellency today received a letter from Mr Michael Lawler resigning as a presidential member of the Fair Work Commission,” she said.

“Mr Lawler's resignation from the Fair Work Commission commences with immediate effect.”

Mr Lawler resigned one day before he was set to respond to a report into his own conduct, by former Federal Court Judge Peter Heeley.

That report covered Mr Lawler’s over nine months of sick leave on his full $430,000 salary.

He spent much of that time helping his partner, former Health Services Union official Kathy Jackson, fight a Federal Court ruling that she inappropriately used $1.4 million of union funds.

Commission president Iain Ross says he approved 215 days of sick leave for Mr Lawler late last year, ruling that he was medically unfit to perform his duties.

“He did not seek and I did not approve leave for the purpose of assisting his partner in legal proceedings,” he said.

The rules of the Fair Work Commission mean that Mr Lawler was entitled to take as much sick leave as he liked, and the FWC could do nothing to discipline or sack him.

If Mr Lawler had not conveniently resigned, both houses of Parliament would have had to vote to remove him.

Opposition employment spokesman Brendan O'Connor welcomed the resignation, but still wants to see Mr Heeley's report.

“Given the gravity of this matter, it is in the public interest that the content of this review, including all findings of Mr Heeley, be disclosed,” Mr O'Connor said in a statement.

“The FWC is a very important institution and has played a significant role for more than a century and Labor has been concerned that its reputation could have been traduced by the conduct of Mr Lawler.”