Tax breaks and fast-tracked permits for controversial shale gas exploration will be offered today as part of a £100 billion Government infrastructure package aimed at kick-starting sluggish economic growth.

New geological data suggesting British reserves of the energy source are much higher than previously thought is expected to be highlighted by Treasury Chief Secretary Danny Alexander.

Mr Alexander is setting out details of the latest round of capital spending, which will also include funds for projects such as new road and rail capacity, science facilities and nuclear power stations, in a Commons statement.

It comes a day after Chancellor George Osborne announced plans to slice a further £11.5 billion off other Whitehall spending in 2015/16 - as poor growth forced him to extend austerity measures beyond the next general election.

Research by the British Geological Survey, to be published today, is said to show far larger quantities of shale gas reserves under the UK - as much as double earlier estimates at one site.

Among those places where drilling is expected to happen is Bolney, near Haywards Heath, where Cuadrilla has a licence.

This is despite widespread local opposition.

Exploiting the natural resource is highly controversial as critics say the process of fracking - fracturing rock with high-pressure liquid to release the gas - can cause earthquakes, pollute water supplies, blight the countryside and affect house prices.

But ministers believe the experience of the US shows it could boost tax revenues, create jobs, reduce energy imports and reduce household bills.

Mr Alexander is expected to tell MPs the Treasury will now move quickly - consulting on a tax break and publishing detailed planning guidance within the next three weeks.

Environmentalists will be concerned over moves for the Environment Agency to offer permits for fracking projects more quickly and to defined timetables in a further bid to encourage firms to invest.

There will also be protection offered for communities affected - with each receiving at least £100,000 in benefits for each well and no less than 1% of the overall revenues.

But Labour's shadow energy minister Tom Greatrex said the move was premature.

He said: "Announcing community benefits and tax breaks before we know how much shale gas is actually recoverable, or before anyone even has a licence to extract it, looks like a desperate attempt to draw attention away from the Government's cuts to infrastructure investment in the Spending Review and its abject failure to get the economy growing."