Europe's vanmakers have gone a long way toward meeting proposals to curb climate-warming emissions, but as debate on the 2016 targets kicks off big auto is seen digging its heels in over the last mile.

European Union ministers meet next week to start the debate, with automakers saying it will be a costly burden at a time when Europe is struggling to emerge from the deepest economic crisis in 80 years.

Manufacturers have been asked to cut van emissions to an average of 175 grams of carbon dioxide per kilometer by 2016, a cut of around 14 percent compared to the 2007 benchmark of 203 grams.

But that could be weakened before powerful automaking nations France, Germany, Britain and Italy give their final approval to the European Commission's proposal.

We'll be keeping a close eye on member states' opening positions next week, said Tom de Vleesschauwer, an auto specialist at consultancy IHS Global Insight.

You can be pretty sure industry will be doing all it can to get the legislation watered down, but it's also a given that there's a big political push in Brussels for the rules to be ambitious.

Except for a handful, manufacturers should have no problems meeting the targets, he added.

Attempts to crack down on car emissions in 2008 were successfully challenged and softened by automakers -- but this time around they face a tough new climate commissioner working behind the scenes, Denmark's Connie Hedegaard.

You should always aim to be as ambitious as technology allows, Hedegaard told Reuters. If you are too hesitant, you risk losing out in the long term.

RAPID GAINS

Auto industry group ACEA says the EU will not achieve its climate aims through technology alone -- van buyers must also be given incentives to choose green during tough economic times, congestion must be tackled and green fuels promoted.

Technologies do not hold the silver bullet, said ACEA spokeswoman Sigrid de Vries.

Vans are built to store goods rather than to be aerodynamic in shape, she added. They are also less suitable for applying breakthrough technologies to cut emissions because of space limitations and costs.

But critics point to the rapid gains made by some manufacturers so far.

The car industry says proposed van CO2 targets are impossible to meet -- That is simply not credible, said Kerstin Meyer from T&E, a campaign group for green transport.

She said carmakers cited exactly the same argument during the battle over car emissions, and yet Ford has already managed to drive down emissions in its Focus car to as low as 99 grams per kilometer.

That's almost the EU target for 2020, Meyer added.

A green version of Europe's best-selling van, the Ford Transit, will be on sale later this year with an 11 percent improvement in emissions over the most efficient Ford Transit available today.

What's possible in cars will also be possible in vans, says auto expert Paul Nieuwenhuis at Cardiff Business School. Most vans are diesels, and car diesel engines have gained so much efficiency in the last few years.

Volkswagen has improved fuel-efficiency and reduced emissions by 10 percent in its new transporter, Europe's third best-seller.

Mercedes says it has made a 13 percent improvement with the new version of its Sprinter, Europe's number four seller, putting it half way to the target.

And Renault says it has made a 15 percent improvement in its new Master van.

ELECTRIFYING

While the targets for 2016 look easily achieved, there is another, longer-term target that looks more challenging -- a cut of about a third to 135 grams per kilometer by 2020.

In fact, ACEA calls that longterm target unfeasible.

Reaching the 2020 targets will require a major shift to the next generation of technology, in particular electrification and diesel-electric hybrids.

Mercedes-Benz says it is starting low level production of electric Vitos this year, delivering 100 vans with a 130 km range.

We're seeing more and more discussion of electrification, said De Vleesschauwer. Small delivery vans being electrified might be pushed through as a compromise.

And the switch to the other big option, diesel-electric hybrids, might be easier than for cars, says Nieuwenhuis.

One of the things that is holding back diesel hybrid cars is the noise, vibration, harshness -- but in vans that's less of an issue. So it is relatively easy to hybridize vans.

Carmakers will be helped by the way van buyers look at the costs, said Nieuwenhuis.

Businesses look at cost in a completely different way to private car buyers -- they look less at the purchase price and more at the lifetime cost, he said.

One UK supermarket chain was saying they get a payback on their experimental electric vans in about five years, he added. Businesses will be quite pleased with vans that return the fuel savings you'd get at 135 grams of CO2 per kilometer.

(Editing by Keiron Henderson)