BNP leader to attend Copenhagen climate conference
Mr Griffin claims there is an 'Orwellian consensus' on climate change
BNP leader Nick Griffin, who has said global warming is "essentially a hoax", will be at the Copenhagen climate change conference.
The MEP will be there representing the European Parliament, as he sits on its environment committee.
The BNP said he would be "the only politician there prepared to say that the science is somewhat dodgy".
Green Party leader Caroline Lucas told the BBC any suggestion he would have any real influence was "a myth".
Delegations from 192 countries will hold two weeks of talks in Copenhagen in December aimed at establishing a new global treaty on climate change.
In a speech to the European Parliament last week Mr Griffin claimed those who warned of climate change were "anti-western intellectual cranks" and described climate change as "a secular religious hysteria".
A BNP spokesman said his appearance in Copenhagen would be a "big opportunity" for the party because "people assume we are only a one-trick pony only interested in race and immigration".
Caroline Lucas on the Green Party's Copenhagen targets
But Ms Lucas, who is also an MEP, told BBC One's Andrew Marr Show: "He is one of a number of members of the European Parliament who will go on a delegation.
"He won't get the right to speak. The Parliament sadly doesn't even get the right to really influence the decisions at all.
"So this idea that somehow Nick Griffin is going to have any real influence on what happens in Copenhagen is a myth."
Climate Change Secretary Ed Miliband said Mr Griffin's views were "irresponsible and wrong", adding: "He will not be part of the formal Copenhagen negotiations and rightly he will not be listened to by anyone with any credibility who is part of these negotiations."
Lib Dem home affairs spokesman Chris Huhne, a former MEP, said: "Nick Griffin was always going to get some role in the Parliament, because jobs are divvied up fairly.
"The crying shame is that he is representing Europe at a key summit for the future of humanity, when he does not even concede that man-made climate change exists."
Ms Lucas warned on Sunday that while momentum was building towards getting binding legal agreements on climate change at the conference - there was a question mark over whether targets would be "anywhere near high enough, ambitious enough, to really avoid the worst of climate change".
International Development Secretary Douglas Alexander told the BBC the biggest risks for the Copenhagen summit were "denial" and "defeatism".
He added: "Actually I think we have seen real progress this week although we need to see a lot more progress in the days between now and the conference starting at the weekend."
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