TORONTO - An Ontario cabinet minister was forced to apologize Tuesday for a tweet accusing the prime minister, Ontario's Opposition leader and Toronto's new mayor of being bigots.

But provincial Opposition Leader Tim Hudak said the wording of the apology made the situation even worse and called for the premier to fire the minister.

Glen Murray, Ontario's minister of research and innovation and a former mayor of Winnipeg, posted to his Twitter feed a comment from another user on Saturday about Toronto's mayoral race.

The tweet slams Toronto mayor-elect Rob Ford, Hudak and Stephen Harper.

"Ford, Hudak and Harper - the trifecta of Republican-style, right-wing ignorance and bigotry," the tweet reads.

The Twitter user posted that in response to a tweet from Murray saying a vote for Ford was a vote for bigotry.

Murray issued a statement the same day Hudak raised the issue in the legislature -- three days after he originally posted the tweet -- saying he doesn't think any of the three men is a bigot.

"I regret tweeting a message that said otherwise, and am sorry that I did," Murray said.

But the apology statement contained several other paragraphs hinting at hate within Hudak's ranks.

"I do challenge Tim Hudak to condemn strongly the hateful campaigning deployed in Toronto and to root out any of those working in his ranks who would try to exploit hatred with smear tactics," Murray said.

Hudak didn't accept the apology.

"I am insulted by minister Murray's refusal to take responsibility for his own statements," he said.

"The right thing to do would be to offer a clear and unconditional apology, not throw more baseless accusations."

If Murray doesn't do that, Ontario Premier Dalton McGuinty should fire him, Hudak said.

A radio advertisement broadcast over the weekend on the Canadian Tamil Broadcasting Corporation suggested people should vote for Rob Ford because he is married to a woman.

Ford said his campaign had nothing to do with the ad and condemned it. It is not clear who sponsored the ads.

Smitherman and his husband Christopher Peloso have an adopted two-year-old son.

Hudak raised the tweet Tuesday morning in the legislature, calling the comment libellous and demanding McGuinty get Murray to apologize.

"It is unbecoming of a minister of the Crown," Hudak said.

"Sir, if you don't call for an immediate public apology from the minister, will you then ask him to resign? This goes way across the line."

McGuinty would not say he would ask Murray for an apology, saying politics can get heated.

"It can involve a very healthy collision of ideas, contrasting perspectives, different ideologies and by and large that is healthy," McGuinty said.

"But once in a while people say things which they later regret and I'm not going to assign blame to any individual who offered any commentary of any kind, which they may choose to regret today in hindsight."

Hudak responded that Murray's comments on Twitter went beyond ideology to "serious accusations of bigotry."

Murray won a byelection for the Liberals in February in the riding Smitherman once held.

In 1998, Murray became the first openly gay mayor in a major Canadian city when he won the Winnipeg race.

Ford said he wouldn't comment on the tweet. A spokesman for Harper did not immediately respond to a request for comment.