Rules forcing carmakers to build greener vehicles will be of no use unless measures are taken to convince consumers to buy them, experts have agreed in a debate on the Commission's vehicle-emissions strategy.

With the European Union determined to take the world lead in the fight against climate change, cars – which alone account for 12% of all Europe's greenhouse-gas emissions – have moved into the Commission's line of fire.

The EU executive's recent proposal to introduce binding caps on the amount of carbon dioxide that new cars can emit has created uproar within the automotive industry, which fears that strict new standards will put European manufacturers at a competitive disadvantage with foreign competitors and lead to massive job losses and delocalisations towards low-wage countries.

Furthermore, automakers say that they have already made significant reductions over the past decade through technological improvements and lay the blame for slow progress on other factors.

But, since European car manufacturers signed a voluntary agreement with the Commission in 1998 to reduce average fleet CO2 emissions to 140 grammes per kilometre by 2008, they have only succeeded in bringing the figure down to 163 g/km. The Commission wants emission levels down to 120 g/km by 2012.