The president of Manitoba's largest union says provincial wage-freeze legislation forced workers at a Brandon hospital lab to agree to a contract that will make it harder to recruit and retain staff.

On Tuesday, employees at Westman Lab voted to ratify their employer's final offer, after more than three years without a contract.

The offer includes wage increases of zero per cent for two years, followed by .75 per cent and one per cent increases.

Michelle Gawronsky, president of the Manitoba Government and General Employees Union, said employees at the lab feel betrayed by their employer. Staff at Westman are paid a minimum of five per cent less than all other Manitoba technologists, she said.

"They are disheartened, they're angry, they're upset, they're disappointed," Gawronsky told CBC News. "They feel extremely disrespected and extremely undervalued."

The union, which represents about 110 technologists at the lab, said in a statement that employees were left with "little choice" but to accept the offer thanks to recent wage-restraint legislation from the provincial government.

"The reality is, recruiting and retaining skilled and experienced lab technologists in Brandon just got infinitely harder," Gawronsky said in the union's statement on Wednesday.

"For more than 20 years, our regional health authorities have been working to standardize compensation in our labs to prevent this very problem. People should be paid the same wage for the same work. This is a big step backwards."

The union said in April that high staff turnover and lower wages were already putting diagnostic services at the lab at risk.

"Manitobans have a real risk here of losing a specialized lab that has always provided that protection for us," Gawronsky said.

She has previously said Brandon lab employees would have had their wages increased to match technologists in other regions if they had reached a deal a year ago, when workers elsewhere ratified a new collective agreement that included retroactive pay.

Legislative challenge coming: MGEU

The MGEU says it and other unions will be launching a constitutional challenge of the province's wage-restraint legislation, which the union says will help technologists at Westman Lab.

Gawronsky said Thursday the union had concerns a potential strike would drag on without conclusion. If striking workers made it to arbitration, the arbitrator would still be bound by the legislation.

"It's a scary place to be. It really is," she said. "These folks work 24/7 trying to maintain and make sure that we're protected as Manitobans. All they're asking for is to be treated fairly and equitably. They're not asking for anything extra."

The union hopes to proceed with a constitutional challenge sooner than later, she added.

​"We're looking at doing it as soon as would be reasonably possible, given whatever direction the government goes in," Gawronsky said. "So we're going to try."