The auto industry will have to cut carbon dioxide emissions from new vans sold in the European Union by 14 percent by July 2013 or face fines, a draft EU document shows.
The ban would be a year later than first envisaged.
The European Commission's new proposal -- due out in October -- looks set to mirror last year's clampdown on cars, which was weakened by a range of concessions and softer fines after a successful challenge by the powerful auto industry.
The plan is likely to spark an intense battle in Europe as member states shield their national champions in the midst of an economic downturn.
Van makers face fines of 120 euros ($175) per vehicle if they fail to meet the targets, according to the draft document, obtained by Reuters. Those that miss by less than 3 grams will receive softer penalties.
The proposal is part of EU efforts to lead the way on battling climate change as it heads into global negotiations on finding a successor to the Kyoto protocol.
European Commission President Jose Manuel Barroso has pledged that if re-elected he will take radical action to tackle emissions from transport, which have grown by about 35 percent in Europe since 1990.
The proposal on vans will be central to that initiative.
Carbon dioxide emissions from commercial vehicles of less than 2.6 tons will be capped at 175 grams from July 2013, a year later than the original plan to cap them from 2012.
EU sources say van makers are already pushing hard for the target to be phased in slowly and for a softening of a separate long-term target of 135 grams by 2020.
In a depressed market, the effect could be a 10 percent price penalty in the showroom, industry group ACEA said in its September newsletter.
Environmentalists said the industry has already adapted quickly to last year's caps on car emissions, after years of exaggerating the impact on costs, and vans will be no different.
Barroso will have to resist sustained lobbying if he is to fulfill his pledge to decarbonizes the European transport system, they added.
The draft proposal foresees exemptions for niche makers of vehicles whose annual production amounts to fewer than 1,000 units.
Land Rover is expected to push hard in coming months for a wider exemption that would cover its rugged Defender model, which is less suited to emissions cuts as it needs to remain low-tech for easy off-road repairs.
The proposal also allows manufacturers to fulfill 3 grams of the cuts through innovative technologies, such as solar panels on vehicle roofs.
(Reporting by Pete Harrison; Editing by Dale Hudson, editing by Anthony Barker)