EU Environment Commissioner Stavros Dimas said on Wednesday he intended to reject the plan, which would have allowed British industry to pump out an additional 20 million tonnes of carbon dioxide (CO2), the main gas blamed for global warming, in the 2005-2007 period.

The decision had been expected to go through a so-called "written procedure", which does not require discussion by the 25 EU commissioners themselves.

But the staff of Trade Commissioner Peter Mandelson, a Briton, blocked the procedure, Mandelson's spokesman said.

"We blocked the written procedure in order to seek further clarity on the decision," Peter Power said.

EU officials have said the UK plan would be rejected on procedural grounds because the revisions were sent past a required deadline.

The European Union's emissions trading scheme sets limits on how much CO2 can be emitted by high-polluting factories such as power stations and oil refineries.

Companies buy or sell rights to pollute, based on limits set by national governments and approved by the Commission, the EU's executive arm.

Britain ran afoul of the Commission for making changes to its original plan that would allow British industry to pump out nearly 3 percent more C02 in 2005-2007 than first foreseen.