The EC wants all EU member states to make it mandatory for cars to have sidelights on in the daytime, and for all new cars to be fitted with lights that turn on whenever the engine is running.
The proposals aim to save between 1,200 and 2,000 lives a year in the EU by making cars more conspicuous to other road users.
The UK government opposes the idea, but admits that it is losing the argument and would be unable to veto a European directive.
Road safety minister Stephen Ladyman fears the move could endanger motorcyclists, who tend to use their headlamps during the day to help them stand out in traffic.
Ladyman told the Commons: ‘Because motorcycles use daytime running lights they have greater visibility than they would do if everyone used such lights.
‘Given that one of the most serious problems we face in this country is to bring down sharply the stubborn rate of motorcyclist fatalities, we cannot afford to compromise an important safety concern for motorcyclists.’
Paul Smith, founder of the Safe Speed road safety campaign said: ‘It is completely obvious to us that making motorised vehicles more visible also makes pedestrians, cyclists and motorbike users relatively and dangerously less visible.
‘I am certain that adoption of this rule would increase casualties among pedestrians, cyclists and motorbike users. We must not allow Eurocrats to have such effects on British citizens.’
Other motoring groups have voiced concern that having lights on during the day would result in increased fuel consumption and CO2 emissions.
Volvo cars already have their sidelights on whenever the engine is running. They are built in Sweden, where the law already states that drivers should have their lights on all the time.