Alberta's challenging Saskatchewan's ban on vehicles preventing vehicles with Alberta plates from being on provincial road construction sites.

Jared Wesley is an associate professor of political science with the University of Alberta, and said in a tweet that Saskatchewan's move is in contravention of three of five components of the New West Partnership Trade Agreement between the three westernmost provinces.

The three components he said the move violates are that British Columbia, Alberta, and Saskatchewan have committed to:

- Be fully transparent, and notify each other of any proposed measure that is covered by the Agreement. The objective is to ensure that new measures do not create new impediments.

- Treat businesses, investors and workers of the other two provinces at least as favourably as they treat their own or those of another jurisdiction.

- Avoid measures that operate to restrict or impair trade between or through their territories, or investment or labour mobility between them.

Now the Alberta NDP government hopes an arbitration panel under the New West Partnership also finds the trade goes against the agreement.

Last week Saskatchewan Premier Brad Wall took to social media explaining the move as retaliatory since the Alberta government has "done much to restrict free procurement and trade" through giving grants to small, Alberta-based breweries to offset an increase in cost, and by not allowing - according to the Saskatchewan Heavy Construction Association - Saskatchewan plates on government of Alberta construction sites.