Prime Minister Jean Chrétien called an Alberta Alliance MP "stupid" Thursday for preventing the House of Commons from making Nelson Mandela an honorary Canadian citizen.

The MP, Rob Anders, shouted "no" Wednesday when the Speaker asked if everyone agreed with the motion.

But it was other words later attributed to Anders that drew Chrétien's ire.

The Liberal MP who presented Wednesday's motion, John McCallum, said Anders called Mandela a former "Communist and a terrorist."

Chrétien said he was stunned by the Alliance MP's comments about South Africa's first black president who fought to end apartheid.

"I think it's horrible, absolutely horrible to call Nelson Mandela ... I will not repeat the term used," the prime minister told reporters. "He's stupid."

The MP, who represents the riding of Calgary West, defended his move Thursday.

"He's the politically correct kind of 'lib' left poster-boy of today," Anders told CBC Newsworld. "I would say that 30 years from now Nelson Mandela will not be lionized as much as he is today."

The Alliance MP admitted that one of the reasons he refused to back the motion is because the Liberals blocked his party's attempt to honour the 50th wedding anniversary of Queen Elizabeth and the Duke of Edinburgh.

"It's got to be quid pro quo here," Anders said.

McCallum said he's incensed by the "ridiculous and ignorant" arguments for denying unanimous consent.

"Every once in a while you can count on a little bit of nasty sludge emerging from the Canadian Alliance woodwork," the Liberal MP said.

"(Mandela) is not a terrorist, he is a freedom fighter," McCallum argued, and "a great icon of the human spirit."

"The whole thing is a massive embarrassment," McCallum added. "It makes Canada look extraordinarily foolish that our whole point of view should be influenced by one individual."

Other parties were quick to denounce Anders as well. NDP Leader Alexa McDonough got a standing ovation during question period Thursday when she referred to it as a petty act that needs to be corrected immediately.

Chrétien, meanwhile, has vowed to give Mandela honorary citizenship "one way or another." The motion may be reintroduced in the Commons after discussions with party House leaders, or it may be dealt with separately as an executive order from cabinet.

Mandela is scheduled to visit Canada this fall. It's expected to be his last trip to North America.