Lawmakers in Brussels voted 379 to 248 in favour of a 90-percent cut in greenhouse gas emissions compared to 1990 levels -- a key milestone towards the 27-nation bloc's goal of becoming carbon neutral by mid-century.

In line with what was agreed by EU environment ministers after marathon talks last week, they left room however for changes and included a string of sweeteners slammed by environmentalists.

"This climate target is a 90-percent cut to carbon pollution on paper only, and full of so many loopholes and caveats that it will likely fall far short," said Greenpeace EU climate campaigner Eva Corral.

From 2036, international carbon credits will be allowed to count towards five percent of the 2040 goal, according to parliament, potentially reducing the share of domestic cuts.

Lawmakers backed postponing by one year to 2028 the introduction of an emissions trading system for fuel combustion in buildings and road transport known as ETS2 -- a scheme sponsored by Scandinavian countries but disliked by Poland and Hungary.

They also said the European Commission should assess progress towards the emissions goal every two years, and propose amendments if necessary, including to the target itself.

Parliament will now have to negotiate a final version of the text with member states.

Behind only China, the United States and India in terms of emissions, the EU has been the most committed of the major polluters to climate action and has already cut emissions by 37 percent compared to 1990 levels.