STRASBOURG European Union lawmakers demanded on Tuesday a full assessment of potential environmental damage from a planned pipeline to pump Russian gas under the Baltic Sea to Germany.
But the company building the Nord Stream pipeline said the move would not delay the bitterly disputed project, and the EU's executive said impact studies were already under way.
The European Parliament endorsed by 542 votes to 60 a non-binding report calling on the European Commission to make a new investigation of the pipeline's impact.
Brussels has already identified the pipeline, a joint venture involving Russia's Gazprom, and Germany's E.ON and BASF, as a key project to ensure secure gas supplies for Europe.
But it has been criticized in Poland, Lithuania and Estonia, angered at being bypassed by a key gas supply route, as well as in Sweden on environmental grounds.
"The European Parliament... calls on the Commission to evaluate the additional impact on the Baltic Sea caused by the Nord Stream project," a key line in the report said.
Nord Stream's 1,200 km (750 mile) twin pipelines would cut through the economic zones of Finland, Sweden and Denmark, so under international law only their assent is needed for construction.
Maartje van Putten, EU Affairs Representative for Nord Stream, told Reuters the vote would affect neither the speed or cost of the project.
"The contracts for the most important parts have been signed already," she said. "Everything is on track according to the decision process of the national authorities."
A European Commission environment spokeswoman said impact assessments were already under way in the affected member states and the results must be assessed before the authorities can give their consent or construction can proceed.
"We have neither the means nor the capability to carry out extra environmental impact studies concerning infrastructure projects," spokeswoman Barbara Helfferich said.
The parliamentary committee, which scrutinizes complaints by EU citizens, commissioned the report after Polish and Lithuanian environmental groups complained the pipeline could damage marine ecosystems along their coastlines.
Polish petitioner Krzysztof Maczkowski, who filed the first complaint in May 2006, told Reuters his issue was purely environmental and not political.
"I'm the happiest man in Europe today," he said.
The report said construction could create an ecological disaster if workers disturb Nazi German chemical weapons that have lain on the Baltic sea bed since World War Two amid 80,000 tonnes of dumped munitions.
Nord Stream has yet to present its own impact assessment, which is being carried out by independent consultants.
In an extreme case, the Commission could ask the European Court of Justice, the EU's top court, to halt construction if Brussels were to reject completely Nord Stream's environmental impact assessment.
Swiss-based Nord Stream plans to start work on the pipeline in 2009 and complete it in 2010.
The project, which former German Chancellor Gerhard Schroeder joined shortly after leaving office, sparked fierce controversy among new ex-communist EU member states in central Europe, which accused Moscow of trying to short-circuit them.
Poland's foreign minister, Radoslaw Sikorsi, who was defense minister at the time, even compared it with the 1939 Nazi-Soviet pact that led to the carve-up and occupation of his country.
(Reporting by Pete Harrison, editing by Paul Taylor)