STORY: The vote paves the way for the European Union proposal to pass into law, unless 20 of the bloc's 27 member states decide to oppose the move, which is seen as very unlikely.
The new rules will add gas and nuclear power plants to the EU "taxonomy" rulebook from 2023, enabling investors to label and market investments in them as green.
Out of 639 lawmakers present, 328 opposed the motion to block the EU gas and nuclear proposals, while 278 voted to block the proposals. Some 33 abstained.
This will be a relief to the European Commission, which proposed the rules in February after more than a year of delay and intense lobbying from government and the gas and nuclear industries.
The EU taxonomy is a landmark law designed to clear up the murky world of sustainable investing, by ensuring any financial products making eco-friendly claims adhere to strict standards.