A Manitoba union filed a complaint to Elections Manitoba on Thursday claiming a contractors' association violated election laws with advertisements endorsing a pending construction tendering bill.

The ads, which are paid for by Merit Contractors Association of Manitoba, appeared on social media and on radio supporting fair and open tendering, said Sudhir Sandhu, the CEO of Manitoba Building Trades.

The Public Sector Construction Projects (Tendering) Act is a bill that concerns tenders issued by government and other public sector bodies in relation to construction projects.

It prohibits the issuing of a tender that would require the successful bidder to employ unionized employees for work on the project.

The Progressive Conservative Party of Manitoba pledged to reintroduce the act in its 2019 election platform after opposition parties delayed it in April.

A Merit Contractors Association of Manitoba advertisement was published on the organization's Facebook timeline leading up to the provincial election. (Facebook)

"We think it is completely unfair and illegal to conduct advertising campaigns without registering with Elections Manitoba as required," Sandhu said.

According to the Elections Act of Manitoba, a third party must register with the government after their election communication expenses totals $2,500. An election communication is a message that takes a position on an issue with which a registered party or candidate is associated.

Sandhu maintains the Merit ad campaign exceeds the limit, and the union filed a complaint with the Elections Manitoba commissioner.

Manitoba Building Trades claims the Merit Contractors Associations of Manitoba advertisements don't fall within the rules of the Elections Act. (Facebook)

"We don't take exception to any stakeholder participating in an election within the rules of the laws that exist, and we think it is legitimate for Merit Contractors Association (of Manitoba) to participate in the election," Sandhu said.

"What we don't think they ought to be able to do is to do it with impunity while disregarding the laws of Manitoba that all of us are expected to comply with."

Yvette Milner, the president of Merit in Manitoba, told CBC News in an email that she hasn't seen the complaint by Manitoba Building Trades, but denies any wrongdoing.

"We are of the position that we have not violated any elections rules," she said.

Milner wouldn't say how much the advertisements cost but did say she hasn't heard from Elections Manitoba yet.

CBC News asked the commissioner for Elections Manitoba to confirm the complaint was made or whether the office is investigating, but didn't immediately hear back.

Manitoba Skilled Trades leaders said, at a 2018 rally, the end of project labour agreements means cheap labour will come from outside Manitoba. (Sean Kavanagh CBC)

Controversy over labour agreements

Sandhu has been critical of the tendering act in the past.

The government's pending construction tendering bill would end the practice of project labour agreements for major infrastructure projects, which require non-unionized workers to pay dues and be governed by the same requirements and benefits as their unionized counterparts.

Progressive Conservative leaders have called the agreements "forced unionization" that discourage companies employing non-unionized workers from bidding for contracts.

At a 2018 rally, Sandhu said the act was "a bad deal for Manitoba skilled workers."

Sandhu told reporters the project labour agreements enhance the pool of skilled workers in the province and slow the tide of cheap labour coming from outside Manitoba's borders.

"This is smart business, this is smart economics. This is not about the vested interests of one group of workers. This is about our economy. I would like those dollars staying in our economy," Sandhu said.

Manitoba Building Trades represents more than 8,000 people through 13 member unions.

Progressive Conservative leaders have said the legislation would ensure all workers are treated fairly.