The European Commission has begun action against eight nations that have so far failed to submit details on how they plan to cut carbon emissions.
The second phase of the EU carbon trading schemes begins in 2008
The Commission sent a written warning demanding an explanation, and set a two-month deadline before it would begin legal action.
The nations, including Italy and Spain, were supposed to have submitted the documents by the end of June.
The plans are a key part of a Europe-wide carbon trading scheme.
The eight nations that have failed to submit their "National Allocation Plans" are: Austria, Czech Republic, Denmark, Hungary, Italy, Portugal, Slovenia and Spain.
A European Commission spokeswoman said a "letter of formal notice", which was sent on Thursday, asked why the member states had not "respected the law".
She added that it would also set a two-month deadline before legal action was started.
"If the governments do not respond, or do not respond sufficiently, then we send out a second letter that will tell them that if they do not respond immediately then we will take them to the Court of European Justice," she told the BBC News website.
"We are going to be very severe with member states who are not submitting on time."
The plans are supposed to show how governments aim to cut carbon emissions over the period of 2008-2012.
These national targets underpin Europe's main policy tool for reducing emissions, the EU's Emission Trading Scheme (ETS).
It was designed to deliver Europe's international obligation under the Kyoto Protocol, to cut greenhouse gas emissions by 8% from 1990 levels by 2012.
Launched at the beginning of 2005, the scheme caps greenhouse gas emissions from energy-intensive industries and allows companies to buy and sell emissions permits with each other.
The European Commission is currently in the process of outlining the scope of the second phase that will start in 2008.
The European Commission is scheduled to meet in November when the National Allocation Plans will be assessed.