OFGEM, the energy regulator, has sent one of its senior executives on a mission to Europe to find out from gas suppliers how much gas they are likely to be able to supply to Britain this winter.

The move is intended to ensure that the UK, which has endured tight supplies during recent winters, is fully prepared for the coming cold season. Security of supply is assuming increasing political importance, especially ahead of the publication next month of the Government's energy review. Britain is also becoming increasingly dependent on imports as it runs out of its own supplies of North sea gas. Wholesale gas prices soared last winter, partly as a result of market uncertainties about the availability of gas from the Continent.

According to Ofgem, British customers paid almost pounds 1bn more for gas last winter because the gas pipeline between Britain and Belgium had been operating at less than full capacity.

In an interview with The Sunday Telegraph, Sir John Mogg, the chairman of Ofgem, said: "Our managing director, Steve Smith, has been going to see gas suppliers throughout Europe to find out from them, in anticipation of a tight winter . . . what they see as the possibilities in terms of supplying gas into the UK market.''

Mogg indicated that supplies in the coming winter were likely to be equally tight.

"We have not given a message of being comfortable because . . . what is important for any regulator is to give it as it is,'' he said.

Nevertheless, Mogg stressed that with new storage capacity as well as new pipelines being built, more supplies would be coming on stream.

"The picture is going to be tight, but the general appreciation at this stage is that if everything happens, we start to get to a very healthy position with regard to supplies,'' he said, adding that "we are more aware of constraints on supply than we were last year''.

Mogg, who is also the chairman of the European Regulators' Group for Electricity and Gas and president of the Council of EU Energy Regulators, said he was convinced that Brussels was "strongly'' committed to an open energy market. Ofgem has previously expressed concern about the levels of competitiveness and transparency in energy markets in continental Europe.

"Is there a political will on the side of the commission [to open up the energy market]? My judgement is, there is,'' said Mogg.

He hailed the recent raids on European energy companies suspected of anti-competitive behaviour. The raids last month followed suspicions that the companies had restricted access to pipeline and storage facilities.

"[This] is a clear message to the industry that they [the European Commission] are serious and that they have information . . . The next stage, if there is to be a next stage, will be the statement of objections.'' If found guilty, the companies could face hefty fines.

According to Mogg, the more Europe's energy markets become integrated, the more Britain will become involved in it.

"The more our gas declines, the more legislation comes from Europe, the more we are involved and the more integrated the market becomes, the more opportunities there are for UK firms to be over there in what is generally a closed market.''