Brown to announce £1bn of help to cut fuel bills

Gordon Brown, the Prime Minister, will use his monthly press conference at Downing Street to reveal the estimated 1 billion package, understood to be mostly funded by the "big six" energy firms.

It will provide grants to encourage people to insulate lofts and fit cavity wall insulation, double glazing and modern central heating systems. Details were being kept under wraps last night but the scheme is likely to favour the over-60s on benefits and families on benefits with children under 16.

It is understood the energy firms will help pay for the package as part of their long-term commitment to cut pollution under the carbon emissions reductions target scheme. A windfall tax is unlikely to be levied on the firms, despite demands from 100 Labour MPs and numerous trade unions.

However, consumer experts were quick to warn that households were unlikely to be able to implement the measures in time for winter.

Ann Robinson, of uSwitch.com, said: "These measures will take some time to roll out and longer to start bearing fruit – they won't be helping people this winter."

Mike Weir, the SNP energy spokesman, said: "If Mr Brown's much-vaunted package comes to little more than a promise of greater energy efficiency measures in the future, then Scottish consumers face a bleak winter."

The measures are likely to build on the Warm Front scheme in England. This awards grants of up to 2,700 to people on benefits and has helped 1.7 million households since 2000.

A separate scheme is run by the Scottish Government. In May, it revealed that its fuel poverty programmes missed nearly one million Scots in need as those receiving central heating systems were not badly off in the first place.

The Tories accused the government of trying to win positive headlines after cutting the Warm Front budget by stealth last year. They said almost 40 per cent of UK homes lacked basic insulation.