Protestors chained themselves to a site in Chesterfield in the early hours of the morning in protest against the controversial hydraulic fracturing or ‘fracking’ process used to extract shale gas.

Twenty members of the group Frack Off targeted a site owned by PR Marriott, a contractor for shale gas firm Cuadrilla Resources which is drilling at several locations including one near Blackpool.

Four protestors locked themselves by the neck with d-locks – more commonly used for bicycles – to a gate at the entrance to the site, where a drilling rig was being stored. Police say the protestors had been moved along by midday.

The protestors said they were concerned the “scale” of fracking now expected in the UK could result in “the total industrialisation of the British countryside”.

Elsie Walker, from Frack Off said: “The scale of development proposed is being completely ignored. Cuadrilla wants to drill 800 wells in Lancashire alone… There are several companies going after several types of unconventional gas in the UK and all potentially on a similar scale to Cuadrilla.”

PR Marriott, which employs around 50 people at its Chesterfield site, said in a statement: “Despite the best attempts of the protestors to damage this British business, access to the site has been gained and work has all but returned to normal”.

This is not the first time shale gas exploration has been targeted in the UK, as in December last year Cuadrilla’s drilling operations were disrupted when activists broke into their Blackpool site and attached themselves to machinery.

Fracking has attracted criticism from environmentalists who worry the process – which blasts a mixture of water, chemicals and sand into the ground to force open cracks in shale rock and let gas flow out freely – could contaminate groundwater.

An independent report commissioned by Cuadrilla found it was “highly probable” fracking caused a series of tremors near Blackpool last year.

The UK Government has given the process the go-ahead following an investigation into its environmental impact.

The ‘fracking’ process which extracts shale gas from shale rock is unfairly criticised for environmental damage and gets unbalanced coverage in the media.

That’s according to a group of Texas-based university researchers in a report released yesterday.

Campaigners have been highly critical of the process, suggesting it is an untested method with an unknown environmental impact.

The Energy Institute at The University of Texas at Austin says it funded the study “to inject science into a highly charged emotional debate”.

The University researchers studied environmental and health effects linked to fracking in three large shale plays in America – one of which is in Texas.

These included groundwater contamination, which has been the biggest focus for anti-fracking groups, as well as the toxicity of hydraulic fracturing fluids, atmospheric emissions and drilling waste disposal.

They found no evidence of aquifer contamination from hydraulic fracturing chemicals in the subsurface by fracking and saw no leakage from fracking deeper underground.

Instead, many related problems were actually common to all oil and gas drilling operations, such as casing failures or poor cement jobs, said researchers.

Charles ‘Chip’ Groat, an Energy Institute associate director who led the project said: “These problems are not unique to hydraulic fracturing.”

The study also found media coverage of shale gas disproportionately weighted: roughly two-thirds of stories it examined showed fracking in a “negative” light.

On top of this, the scientists say less than 20% of newspaper articles on hydraulic fracturing mentioned scientific research.

Mr Groat added: “Our goal was to provide policymakers a foundation for developing sensible regulations that ensure responsible shale gas development. What we’ve tried to do is separate fact from fiction.”

The American legal profession is to hold a conference on the topic of hydraulic fracturing, or ‘fracking’; the controversial drilling technique of releasing gas from shale rock.

Taking place in December in Dallas, experts from the legal profession will discuss topics relating to the fracking process such as the role of government; health and environmental risks; discovery; damages; contamination and injury cases.

Tom Hagy, CEO of conference hosts Hammons & Baldino LLP said: “The increased use of fracking to extract natural gas from underground rock formations raises environmental and legal challenges and will be the topic of discussion by attorneys, professors and scientists at this program.”

The group say they are responding to the need for a clearer legal framework for the infant industry, which has often come under fire for environmental damage.