Labour leaders are trying to pressure the Nova Scotia government to change its mind about slashing the number of labour bargaining units representing health workers.

Health Minister Leo Glavine says the bill he'll introduce on Monday will spell out which union will represent nurses, technologists, administrative and support workers. Employees will not get a vote, under the proposal.

The bill will also allow a mediator to work on existing contractual differences across 50 bargaining units.

Around 100 supporters gathered on the steps of Province House for an impromptu rally Friday morning.

Nova Scotia Government and General Employees Union president Joan Jessome say she'll fight the province's plan to designate unions.

Labour leaders address the crowd at Province House. (CBC)

Jessome represents the largest number of health workers affected by the proposed change.

"NSGEU has 14,000 health-care workers impacted by these decisions that are going to come into the legislature on Monday night," she told the crowd.

"There is no way in good grief and in good conscience could I ever as a union leader sit down and negotiate away benefits from members when they have no say."

Saint Mary's University professor Larry Haiven calls it an outrageous union-busting move aimed at the NSGEU.

"Can you imagine if the government said, 'This whole legislature thing is very unwieldy. So we're going to streamline it. What we're going to do is reduce the number of constituencies in Nova Scotia to four and you know this voting stuff? Forget about that because that's very inefficient so we’re going to appoint the MLA for each of the four remaining ridings and you’ll get over it,'" he said.

Opposition MLAs say the government should allow people to decide for themselves who will represent them.

"We're seeing a whole package of policies out of this government that are really hostile to people who work on the front lines of health care, rather than dealing with the problems that are in the health-care system," said interim NDP Leader Maureen MacDonald.

Premier Stephen McNeil says the health merger will be better for everyone in the long run.