A gas exploration company has said it can drill hundreds of wells in Lancashire to tap into vast shale gas resources underground.
Cuadrilla Resources said there were 200 trillion cubic feet of gas under the ground in the area and could recover a percentage of the gas for use in the UK's energy mix.
This could provide up to 5,600 jobs, including 1,700 in the local area, at the peak of production, Cuadrilla suggested.
"We're really happy with what we are finding," said Mark Miller, chief executive of Cuadrilla, adding the company was "pleasantly surprised" by findings of the exploration phase.
Campaigners against shale gas have warned that developing the fossil fuel could draw investment away from the UK's potentially huge renewable industry which could provide £100 billion in investment opportunities and up to half a million jobs by 2020.
The Co-operative, which has been campaigning against unconventional fossil fuels including shale gas and tar sands, warned the government not to be "seduced" by the new gas field.
"On the face of it new natural gas finds appear to be good news, but the government must not be seduced by this without considering all the impacts of shale gas extraction," said Paul Monaghan, head of social goals at The Co-operative.
"That is why we are calling for a moratorium on any further exploitation of shale gas which will allow the wider environmental concerns to be fully exposed and addressed."
Friends of the Earth's senior climate campaigner Tony Bosworth said: "Drilling for shale gas raises serious safety concerns and risks polluting water supplies - and it could take vital funding away from the clean energy solutions we know are safe and will work.
"There should be no more fracking in Britain until safety and environmental concerns have been properly addressed."
Jenny Banks, energy and climate change policy officer at WWF-UK, said: "There has still not been enough research into the issue of water contamination by shale gas extraction.
"If we're serious about tackling climate change, we should be looking at building up a strong renewable industry in Britain, not another fossil fuel industry."
The gas is found in shale formed from deposits of mud, silt, clay and organic matter.
It is extracted by drilling down into the ground and then by "fracking", a process of hydraulic fracturing of the shale using high pressure liquid to release the gas.
It has proved controversial in the US, where shale gas is already being exploited on a large scale, because the drilling process involves chemicals, including cancer-causing compounds, which can pollute water supplies.
There are also claims that the gas itself can pollute drinking water, with footage of people able to set fire to the water coming out of their taps.
The problems have prompted campaigners to call for its exploitation in the UK to be banned, a suggestion ruled out earlier this year by a committee of MPs who found no evidence it would pose a risk to water supplies from underground aquifers.
Miller said the process would not pose a threat to UK groundwater and that the wells - as many as 400 over the next nine years and up to 800 over 16 years if gas extraction is successful - could be grouped in units of 10 on each football pitch-sized site, reducing their impact on the landscape.
Each well is drilled and then fracking takes place over several weeks, after which the well can potentially produce gas for up to 30 to 50 years, he suggested.
He added: "When they are done right, someone driving by on a country road or walking their dog, it will be hard for them to see our sites as they will blend in with the Lancashire countryside."
While the recoverable amount of gas would be only a proportion of the 200 trillion cubic feet underground, and it was too early to put a figure on the reserves, he predicted it would be a "significant" amount.
Miller said the company would finish the exploration phase and then begin the process of getting approval over the next two years to exploit the shale gas, which would either be piped underground from the sites or used to make electricity in situ.
Cuadrilla will also be releasing a report into the two tremors which were recorded near to the Blackpool drilling site in April and May which caused exploration to be suspended, he said, adding that the findings will restore the confidence of the public and relevant authorities.
He estimated as much as £2 billion could be invested in drilling the wells, and while it was "too early to tell" what the returns could be, Cuadrilla estimates that local authorities could benefit from £120 million in business rates.
Frost & Sullivan Energy consultant Jonathan Robinson said: "Analysts expected shale gas would be found – Blackpool sits on one of three major shale gas basins in Europe, known as the Carboniferous marine basin - but the size of the find was more than expected.
"Based on a reasonable assumption that 20 per cent of the gas is recoverable, this means that the UK has gained 40TCF of gas reserves.
"The UK’s gas reserves have been declining for some years now and the country is becoming increasing dependent on imports.
"If results like Cuadrilla’s keep coming in, shale gas could well prove to be the energy game-changer in Europe that it has been in the US - and this would have far reaching implications beyond just the energy sector."