Canada's marijuana laws absorbed another punishing blow yesterday when a Toronto judge concluded that the law is invalid and acquitted a man of possession.

Ontario Court Judge John Moore added momentum to a string of recent court rulings that have pummelled the law, saying their combined force leads down "a common-sense path."

Judge Moore endorsed a ruling by a Windsor, Ont., judge last week. He said the government erred when it created regulations to govern medicinal marijuana without enacting them in Parliament as legislation. He said the procedure was at odds with instructions from the Ontario Court of Appeal in a 2000 ruling.

Judge Moore also denied a federal request to hold off on the case against Martin Barnes until the Windsor ruling could be appealed.

The chain of events signifies that as with abortion, so with marijuana: The courts are slowly, but surely, forcing Parliament to put up or shut up.

The decisions have tightened a noose activists began fashioning years ago, when they realized that their best chance for marijuana reform lay with the judiciary.

On Thursday, an Ontario Superior Court judge ruled that a marijuana-distribution scheme for the ill was so inaccessible as to render it unconstitutional.

The same day, a judge near Ottawa acquitted ex-lawyer Rick Reimer of the rare charge of impaired driving caused by marijuana. Ontario Court Judge Bruce McPhee said he was left with reasonable doubt as to whether Mr. Reimer was impaired when police stopped him with a joint in his hand.

At the same time, a major decriminalization challenge is burning a hole in the Supreme Court of Canada docket. It could be heard as early as next spring.

The scenario has echoes of the battle over abortion rights, which reached its peak in a 1988 Supreme Court of Canada ruling that struck down the existing abortion-law regime.

When the federal government failed in a subsequent attempt to create a new law, the abortion war was effectively over.

"Parliament now has a chance to either bring in a marijuana decriminalization bill or just let the laws die judicially," said Alan Young, one of several lawyers who worked on a litigation strategy.

He said in an interview that he believes that the latest rulings "will be the final nail in the coffin."

He predicted that if the government tries to cut its losses by setting up a truly accessible distribution scheme for the ill, it will swiftly recognize how much money can be made from marketing marijuana.

Decriminalization will quickly follow, he said.