Ambrose, the focus of attacks from the media, opposition parties and green groups, flew to Nairobi on Sunday for UN climate change talks on finding a successor to Kyoto, the first stage of which ends in 2012. Signatories to the protocol are gathered in the Kenyan capital for a two-week conference.

Ambrose is the outgoing president of the talks but rather than attend the opening last week she sent a video of remarks instead, to the irritation of some delegates.

Opposition politicians, saying the planned clean air law would damage Canada's international reputation, demanded Prime Minister Stephen Harper stick to the first stage of Kyoto and also agree to binding long-term targets.

"What we are asking is that (he) change a course which is a disaster for our environment, a disaster for our foreign policy and a gross abandonment of our responsibility for the world," said Liberal leader Bill Graham.

Canada's three opposition parties have a majority of seats in Parliament and say they will block the clear air bill. All three are sending legislators to Nairobi and vow to openly criticize Ambrose.

HYPOCRISY ACCUSATIONS

The Conservatives, who won power in January, paint the Liberals as hypocrites who did nothing about Kyoto after winning an election in 1993.

"Now (they) have the gall to actually suggest they would go to Nairobi and commit us to even more targets while we are still waiting to see their plan after 13 years," Harper said.

Kyoto committed Canada to cutting emissions by 6 percent from 1990 levels by 2012. Emissions are now 35 percent above that target and are set to rise more rapidly as oil-rich tar sands are opened up in western Canada, which happens to be the Conservatives' power base.

Ambrose says Canada needs a different approach to global warming but denies it will follow the lead of US President George W. Bush and pull out of Kyoto altogether.

"Canada is on track to meet all of our Kyoto obligations except for our target," she told Parliament last week in the kind of comment that has prompted increasing mockery.

In her year as president of the talks she briefly attended one conference on the environment and skipped two others.

"(She) is missing so many meetings that her international colleagues are thinking about putting her face on a milk carton," remarked Liberal legislator Lucienne Robillard.

Toronto Star columnist Chantal Hebert said Ottawa's effective abandonment of Kyoto "casts a pall on the value of Canada's word" to the international community.

"If a country such as Canada can treat its signature on a treaty as a passing inconvenience, how many other nation-states will feel entitled to shrug off cumbersome obligations in the future?" she wrote.

Harper's problem is that green issues are becoming more important to Canadians, especially in the influential French-speaking province of Quebec, where he must boost support if he is to win a majority in the next election.

A poll for the Canadian Broadcasting Corp. last week showed the environment was second only to health care as a priority for voters. Almost three-quarters of those surveyed said the government was not doing enough to fight climate change.