The European Parliament appears split over a proposed law that would force down exorbitantly high mobile phone roaming prices.

The European Commission has proposed a system that caps the cost of making a call abroad at between €0.40 and €0.50 (57p and 73p), and limits the cost of receiving a call from abroad at €0.20 to €0.25. (28p to 36p)

These prices are far lower than most of the roaming charges currently demanded by mobile-phone operators. Germany supports the Commission and hopes to sign off on the law before its six-month presidency of the EU expires at the end of June.

Members of the European Parliament agree with the general idea of regulating prices, but right-of-centre politicians oppose a single tariff for everyone, preferring a system that would allow subscribers to opt in to a single tariff, but otherwise remain with their phone companies.

They prevailed in a discussion in the internal market committee. "Together with the Liberals we managed to prevent a one-size-fits-all solution, based on imposing a single tariff for all consumers as demanded by Socialists and Greens," said Malcolm Harbour, a conservative member of Parliament from the UK.

The committee supported a system where the agreed maximum tariff was offered as an alternative to the price charged by the mobile operator. New mobile-phone accounts opened after the law is passed would automatically be programmed to the opt-out model favoured by the Commission and left of centre parties.

The European commissioner in charge of telecom-related matters said the vote would benefit only some mobile-phone users.

"I find it regrettable that many in the European Parliament want only new customers to profit automatically from cheaper roaming tariffs," Viviane Reding said. "Mobile phone penetration in the EU is today at 103 percent - there are thus not many consumers who would profit from the EU regulation if it would apply automatically only to new customers."

"The whole debate about opt in-opt out is also about who finally will have to be in charge of advertising for cheaper roaming tariffs," Reding said. "I believe the burden of proof should be on the operators to demonstrate that their packages are really cheaper - and thereby to convince consumers to opt out from the consumer protection tariff. If consumers first of all will have to opt in to the cheaper consumer protection tariff, then operators will be able to rely on the passivity of many consumers."

The committee vote was also criticised sharply by consumer groups. "MEPs voted for higher prices. They left most EU consumers ... at the mercy of telecom operators," said Jim Murray, director of the European Consumers' Organisation known by the acronym BEUC.

Meanwhile, the culture committee voted in favour of the Commission's opt-out approach for all, as did the economic and monetary affairs committee. The only remaining committee to give its views on the proposed roaming regulation is the industry committee, which meets to discuss the proposal on 12 April. Then the proposal will be debated and voted on by the full plenary session of Parliament in May.

Once the European Parliament and the national governments, headed by Germany, have agreed on the shape of the new law, it will immediately come into force. If Germany's timetable doesn't slip, then the law will be in place in time for consumers to benefit from the lower prices when they take their summer holidays this year.