The European Union struck a provisional deal on Wednesday to improve the fuel efficiency of vans and curb emissions blamed for climate change.
But the deal was not formally approved by EU member states, most notably Europe's top van maker Germany, and will be put to the vote again by ministers in Brussels on Monday.
EU negotiators agreed to cut van emissions by around 14 percent to an average of 175 grams of carbon dioxide per kilometre by 2017.
That target was not contested as it is widely seen as unambitious, given rapid gains in efficiency recently by van makers -- 15 percent by Renault's Master van and 13 percent by Mercedes' new Sprinter van.
A much tougher long-term target of 135 grams per kilometre by 2020 was softened to 147 grams in the draft agreement.EU climate commissioner Connie Hedegaard welcomed the deal.
"The agreed regulation will make vans less polluting and will contribute to our overall ambition to cut emissions from transport," she said in a statement.
"It will also generate important fuel-savings for consumers," she added.
EU diplomats warned, however, that the deal was not yet done as Germany has so far said it cannot go below 150g in 2020.