If you are working on a new Saskatchewan government highways project, you'd better not have an Alberta licence plate.

The province is banning workers with Alberta plates from all new road projects. The new rule won't apply to existing projects like the Regina bypass.

The Ministry of Highways is targeting Alberta specifically because it says Saskatchewan workers in Alberta feel forced to register their vehicles in order to work there.

"Saskatchewan contractors tell us that vehicles with Saskatchewan plates are not welcome on Government of Alberta job sites," said Highways and Infrastructure Minister and Minister Responsible for SaskBuilds David Marit.

The ban only applies to Alberta. All other Canadian licence plates are welcome on new road construction sites in Saskatchewan.

"There's a handful of Alberta contractors who do work on Ministry of Highways jobs. They'll now just have to register their vehicles in the province of Saskatchewan and pay the PST on the vehicles," Marit said.

Alberta says kill restriction, or else

Alberta's minister of trade said there is no requirement for Saskatchewan workers to register their plates in Alberta.

"Brad Wall needs to smarten up and he has one week to kill this ridiculous restriction, or we're going to be taking him to court," said Deron Bilous, Alberta's minister of economic development and trade.

Alberta Trade Minister Deron Bilous demands Saskatchewan kill restrictions that ban workers with Alberta plates from new road projects. 0:54

Alberta believes the restriction violates the New West Partnership Trade Agreement and is non-trade compliant.

When asked, if he thought the policy was in violation, Marit told reporters he was advised that it may be.

Bilous said the Saskatchewan government did not reach out to Alberta before making the policy change, and added Saskatchewan's premier likes to launch trade injunctions.

"Brad Wall is absolutely desperate. We know our economy is growing by four per cent, their economy is in the dumps. He's grasping at straws."

Bilous said Saskatchewan benefits greatly from Alberta workers.

Deron Bilous, Alberta minister of trade and economic development, says the Saskatchewan policy to restrict licence plates is a violation of the New West Partnership. (CBC) New contracts awarded by the ministry will require suppliers to ensure that no vehicles displaying Alberta plates are present on ministry-funded work sites, including contractors, sub-contractors, consultants and workers.

"Saskatchewan operators have been subject to this treatment in Alberta for years," Marit said. "Today we are sending a clear message that Alberta suppliers can expect the very same treatment here."

But Bilous said Alberta has always welcomed Saskatchewan contractors on its job sites and claims to the contrary are untrue.

The Ministry of Highways will monitor job sites to ensure there is compliance.

Policy 'problematic' says Alberta construction industry

Paul Cashman with the Alberta Roadbuilders & Heavy Construction Association said the policy caught his organization by surprise.

"We weren't aware of any complaints, so it seemed to come out of the blue for us. We did not see this to be a problem," Cashman said.

Vehicles from all provinces and territories will be allowed on new Sask. work sites, with the exception of Alberta. (CBC) The existing policy required heavy equipment registered in Alberta which spends more than 30 days in Saskatchewan to re-register to be a Saskatchewan vehicle.

But, Cashman said, the new policy adds to paperwork requirements, which adds inefficiency and ultimately cost.

"We do think it would be problematic for the industry because it would require vehicles to be re-registered and re-insured for even a short period or for short site visits."

He said the timing of the policy allows for the provinces to work out their differences over the next few months.

"We certainly hope this issue can be worked out well before the construction season begins next summer."

Move applauded by Sask. construction industry

"We are very pleased to see government enacting changes that will level the playing field for our members," said Saskatchewan Heavy Construction Association President Shantel Lipp.

"As local construction companies obtain a larger share of the Saskatchewan construction marketplace, they develop the people, equipment and capacity to maximize their economies of scale."