The government is due later to reveal whether it backs fracking plans, in a landmark ruling for the UK shale gas industry.
Communities Secretary Sajid Javid is deciding on a planning appeal by firm Cuadrilla to test frack in Lancashire.
His backing would enable shale rock to be fracked horizontally for the first time, in a bid to yield more gas.
But, protesters say it uses techniques that risk the environment because of the chemicals and pressure used.
Lancashire County Council refused permission to extract shale gas at two sites – Roseacre and Preston New Road – last year on grounds of noise and traffic impact, forcing Cuadrilla to appeal.
In response, a Planning Inspectorate report was sent to the Department for Communities and Local Government on 4 July, with Mr Javid being given three months to reach a decision on both sites.
The announcement will come after a planning inquiry earlier this year in Blackpool lasted six weeks, during which Cuadrilla restated its case.
If Mr Javid backs the firm’s plans it will not be the first time fracking has been approved since a ban, imposed in 2011 after test drilling led to two earth tremors in Blackpool, was lifted in 2012.
However, it would the first in the UK to involve horizontal drilling.
Horizontal fracking is a technique in which the well is turned horizontally at a set depth, to extract energy from a layer – or layers – of shale rock.
It is seen as more productive than conventional vertical drilling, which goes directly through the a smaller area of a seam.
In May, North Yorkshire County Council approved an application by Third Gas to vertically extract shale gas near Kirby Misperton in Ryedale.
Drilling companies believe trillions of cubic feet of shale gas may be recoverable underneath parts of the UK and more than 200 onshore exploration licences have been awarded to energy companies.