The Supreme Court of Canada ruled it will not hear an appeal by eight former board directors, who accused the government of breaking its own law by making radical changes without first holding a plebiscite among grain producers.
New legislation introduced by Prime Minister Stephen Harper's Conservative government strips the marketing agency of its monopoly on western wheat and barley sales.
As is its usual practice, the high court did not release reasons for its decision.
Agriculture Minister Gerry Ritz welcomed the ruling as "fantastic."
"It turns the page, lets farmers get on with what they do best, which is produce those great high-quality crops," Ritz told Regina radio station CKRM.
It is not the end of the legal battle. Supporters of the wheat board as it was prior to the change have filed a separate lawsuit in Federal Court. They said the Supreme Court rejection will not deter them.
"We have a class-action underway and that action is based on a variety of legal theories that are quite different from what was argued in the case ... that went to the Supreme Court of Canada," said Anders Bruun, a spokesman for the Friends of The Canadian Wheat Board.
The lawsuit seeks a court order to restore the board's monopoly and to give farmers $17 billion in damages.
The wheat board monopoly had forced western producers to sell through the board since the 1940s — unlike their counterparts in other parts of the country.
Supporters said the single-desk approach ensured better prices and prevented farmers from competing against each other for sales. But many producers opposed the monopoly and the Conservatives had promised for a long time to allow farmers to sell to whomever they chose.
In late 2011, the government introduced legislation to end the single-desk in time for the 2012 crop year. Wheat board supporters argued that Section 47 of the Canadian Wheat Board act prohibited the government from making the change without first holding a plebiscite among producers.
A Federal Court judge agreed, but the government appealed. The Federal Court of Appeal sided with Ottawa, saying the law did not require a plebiscite to open up grain marketing. The Appeal Court also said Parliament has the right to change its own laws.
— By Steve Lambert in Winnipeg