Chris Huhne has ordered a private inquiry into which fossil fuel lobbyists "got to" the Conservative MEPs who defied David Cameron and voted down an ambitious carbon emissions target in the European parliament on 5 July.

"I have asked for a full analysis of what happened," said the energy and climate change minister, speaking at an event in parliament. "We thought the vote was going to be close, but it was not close. We want to see which lobby groups managed to get to the MEPs."

New research by the Guardian and Greenpeace into lobby groups and businesses seen by Tory MEPs in 2010 reveals there were more than four times as many meetings with fossil fuel companies, carmakers and others against stronger action on global warming than with green businesses and those pushing for deeper cuts in greenhouse gas emissions.

Huhne, a Liberal Democrat, has caused a storm by comparing Tory campaigning tactics on the AV referendum to those of the Nazis and by repeatedly challenging Cameron at a cabinet meeting on the issue. By investigating the EU climate vote, he risks further increasing tensions within the coalition.

"It is extraordinary for Huhne to instigate an investigation into his coalition partners," said Luciana Berger, Labour's shadow minister for climate change. "It shows Lib Dems and Conservatives are too busy squabbling with each other to take decisive action to reduce carbon emissions."

Huhne had been successful in gathering support from other countries to increase the EU's 2020 greenhouse gas target from 20% below 1990 levels to 30%, arguing it was in the UK's best economic interests. But Tory MEPs were key in carrying a vote against the plan, despite Cameron promising to intervene after their intention was revealed by the Guardian.

"I'm happy for Huhne to investigate whatever the hell he likes. I just wish he'd spend more time investigating the huge economic damage that his green policies will do," said Tory MEP and climate sceptic Roger Helmer. He added: "The prime minister is in no position to 'bring Conservative MEPs into line'. I vote in what I conceive to be the best interests of my country and my constituents: the party whip comes a poor third."

Martin Callanan, leader of the Conservatives in Europe and an environment spokesman, said: "Our position on [deeper emission cuts] has not been influenced by lobbyists and has remained unchanged since the idea was first mooted.

"Europe already has the world's most ambitious targets and, in the absence of a worldwide agreement, forcing business and industry to pay more for their CO2 emissions in Europe will merely result in them relocating outside of the EU."

But a spokesman for No 10 said: "Government policy is, and remains, to persuade the EU to adopt the 30% emissions reduction target."

Callanan said any discussions he had with No 10 were confidential but he added: "Conservative MEPs are the most open and transparent UK members. We publish details of all lobbying meetings."

Chris Davies, the Lib Dem environment spokesman in Europe, said: "The prime minister's promises to lead the greenest government ever sound very hollow indeed when his own party fails to walk the walk on cutting carbon emissions."

The research by the Guardian and Greenpeace (January to June and July to December) shows that the 25 Tory MEPs met at least 300 representatives from fossil fuel businesses and their lobbyists in 2010 at more than 200 meetings, compared with about 70 representatives from green industries or lobby groups. The latter includes meetings on climate change, renewable energy and similar issues, but excludes meetings about unrelated issues such as agriculture and biodiversity.

The research also found the Tory MEPs attended at least 100 meetings with gas and oil companies and 75 meetings with car manufacturers last year.

Ford was one of the most hospitable companies, enjoying meetings with at least nine of the MEPs, most of them more than once.

The Society of Motor Manufacturers and Traders was also popular, alongside Jaguar Land Rover.

The UK's Association of Electricity Producers, which has strongly opposed any increase in carbon emissions cuts, was well-represented among the numerous fossil fuel energy lobbyists, along with oil industry groups such as the UK Petroleum Industry Association.

Meetings with green lobbyists, aside from the many devoted to issues such as the common agricultural and fisheries policies, were far fewer, with WWF figuring a handful of times and Greenpeace once.

Several renewable energy companies enjoyed a little more success, including First Solar which met three of the MEPs.

One member, Giles Chichester, Tory MEP for southwest England and Gibraltar, met the European Wind Energy Association but only at a large energy dinner.

Several green companies also attended a large dinner on food security and climate change attended by Chichester and fellow MEP Julie Girling last December, and a small number of other dinners. By contrast Helmer had four meetings in six months about beer.

"The Conservative party in Europe is in the pocket of big oil," said Berger. "The prime minister needs to get a grip of his party and start leading a government that is serious about tackling climate change."

Martyn Williams of Friends of the Earth said: "There is a huge list of major companies who have told Conservative MEPs that getting serious about tackling climate change will give a boost to the European economy. The MEPs should stop listening to special pleadings and examine the big picture."

Huhne's private office did not respond to requests for comment and a spokesperson at Huhne's department of energy and climate change declined to respond, saying it was a "political" matter.