A Saskatchewan judge has overturned the union certification of a Weyburn Wal-Mart store, saying workers should be allowed to vote on the matter.

It's the latest twist in a battle between the retail giant and the United Food and Commercial Workers union.

The union applied for certification in 2004 after obtaining signed union cards from most of the employees in the proposed bargaining unit. The labour relations board approved certification in 2008.

The law in 2004 was that if more than 50 per cent of employees signed cards, a secret ballot vote wasn't required.

However, after the Saskatchewan Party won the 2007 provincial election, defeating the NDP, the law changed — an employee vote is now mandatory before certification can be considered.

Justice Peter Foley ruled the amended Trade Union Act should have been the basis of the labour board's decision when it ruled on the Wal-Mart case in 2008.

"The UFCW had no vested right to insist on a particular procedure involving membership cards being followed by the board," Foley said in the 11-page decision which was made public Wednesday.

"The board erred in law in not giving effect to the enactment [of Bill 6] and proceeding under the repealed procedure. This error of law rendered the certification order void."

Foley said he was sending the certification order back to the labour relations board so a vote can be ordered.

Neither Wal-Mart nor the union was immediately available for comment.

Gordon Button, a stockroom worker who has been employed at the Weyburn store for the past year and a half, was pleased about the decision.

Button, who thinks there's no need for a union, said employees cheered Wednesday morning when they heard the news.

"This is what I and a few more of the people, we've been fighting for for a long time," he said. "The people that the union had signed up are not here anymore ... and anybody that I've talked to and dealt with, don't want 'em."

There is no word from the union on whether it will appeal. The United Food and Commercial Workers union is also trying to unionize Wal-Mart stores in North Battleford and Moose Jaw.