European ministers will this summer face a crucial decision on whether to formally brand oil from tar sands as carbon intensive, after EU vote on the proposals ended in stalemate.

The vote ended with 89 votes for the proposal, 128 against, and 128 abstentions, leaving the policy well short of the almost three-quarter majority required for it to go straight into law.

The issue will now be debated this June by member states’ ministers, who will face intense pressure from green businesses and NGOs to bring in new rules designed to significantly undermine the attractiveness to EU importers of oil from tar sands.

Under the proposals, oil from tar sands would be labelled as causing 22 per cent more emissions than conventional sources, making them less viable for European companies who are required to cut the carbon intensity of transport fuels by six per cent by 2020 under separate EU rules.

A number of countries voted to block the proposals, but crucially several countries abstained, including Belgium, Germany, France, Cyprus, Netherlands, Portugal and the UK.

Writing on Twitter, Greenpeace campaigner Joss Garman praised Transport Minister Norman Baker for securing the abstention after earlier reports had suggested the UK was pushing for rules governing tar sands oils to be relaxed.

“Respect to Norman Baker,” he wrote. “He shifted the UK’s position on the tar sands vote, and got them out of the way.”

Baker himself said the UK abstained because “the Commission’s proposals were inadequate and incomplete” to deal with highly polluting fossil fuels and pledged to work closely with EU climate commissioner Connie Hedegaard to bolster them.

“We take the treatment of high-emitting oil sands seriously but we want an effective solution to address the carbon emissions from all highly polluting crudes, not simply those from oil sands,” he added.

“The Coalition Government is however keen to get a good environmental outcome and we do not want this matter to end in stalemate with no action being taken.”

Delaying a decision is likely to result in an intensification of lobbying efforts from both sides as green campaigners push ministers to block tar sands imports and the Canadian government and oil firms step up efforts to convince EU governments that such a move would be unfair and counterproductive.

An on-going investigation by the Guardian newspaper has revealed that the Canadian government has been lobbying intensively to undermine the proposals, even threatening that a trade war could result if the EU does look to restrict tar sands imports.

Hedegaard said she was “glad” member states stood up to the lobbying efforts and did not reject the proposal.

“I hope governments will realise that unconventional fuels - of course - need to account for their considerably higher emissions through separate values,” she said in an emailed statement.

“Exactly as Member States’ governments have already agreed when it comes to biofuels, our science-based and non-discriminatory proposal is the right way forward.”