But the NDP deputy premier who introduced the motion conceded that it might not result in the recovery of any money since MacDonald abruptly resigned Wednesday.
Members from all three parties on the legislature management commission voted in favour of the motion, pending legal advice about whether it has the ability to dock the pay of retired politicians.
Frank Corbett put forward the motion to dock MacDonald's salary for the 20 days he was absent without permission. But he later said he had been told by the Speaker's Office that it was unlikely they could demand the salary.
"I guess we're asking for clarity," he said after the meeting. "The point is, just because you get one opinion should you stop there? ... We're trying to make sure we've exercised all of our possibilities."
Corbett, along with other NDP and Progressive Conservative members, voted against a motion by Liberal Andrew Younger to have all members of the legislature subject to the same rule — that their pay can be docked if they are absent without permission.
Younger said it showed the exercise was more about politicking and trying to smear the reputation of the long-serving Cape Breton politician rather than clarifying the rules on absences.
"This is really about trying to get points when they're low in the polls," Younger said. "We agree with the motion to have Manning forfeit his pay for that period of time. We just think it should apply to anybody who is absent."
His party believes there should be an examination of all members' attendance, adding that there have been times when legislature members from other parties have been absent because they were on vacation.
But other parties have dismissed the idea, saying it would be difficult to keep attendance in the house.
MacDonald represented the riding of Cape Breton South for 20 years until he retired from politics Wednesday, a day before his case was set to be dealt with by the committee.
He has said he booked the vacation believing an election would be underway.
MacDonald had decided not to seek re-election and Liberal Leader Stephen McNeil has said he declined attempts by MacDonald to resign last fall and again this spring.
MacDonald couldn't be reached for comment, but in a letter to legislature Speaker Gordie Gosse he offered to make donations to two charities in Cape Breton because of his absence from the house.
"These contributions would be equal and based on the anticipated financial reimbursement decision of the legislature management commission," wrote MacDonald.
Corbett said he didn't know how much that would amount to.
Chris d'Entremont, the lone Progressive Conservative member of the commission, said the Liberals were merely trying to create "a smokescreen" when it was really an issue about a failure of leadership.
"Mr. MacDonald was allowed to go to Florida to play golf and hang out on a beach when the rest of us were here working for Nova Scotians," he said.