Helmer is one of a growing band of European politicians threatening to cause trouble for the Tory frontbench in the first few months of any government it may form. He and his eurosceptic colleagues insist they will not drop their campaign for a referendum on Lisbon.

Analysis by the leftwing website Next Left has shown that the top 10 Tory bloggers are climate change sceptics. This week Helmer convened a conference of climate change deniers at the European parliament. Speakers included Ross McKitrick, a Canadian professor who has said data indicating global warming has been fiddled; Tom Segalstad, a Norwegian geologist who says human-released CO2 would not have a large effect on the climate; Fred Goldberg, co-author of the polemic The Global Warming Scam; Hans Labohm, a Dutch professor who challenges the existence of global warming; and Professor Fred Singer, who wrote the documentary The Great Global Warming Swindle.