Britain’s fracking industry is unlikely to realise its potential unless rules governing earthquakes at drilling sites are loosened, according to the petrochemicals giant with the biggest exploration rights.

Ministers have championed the controversial shale gas extraction technique, giving the go-ahead to the first operation in the UK for seven years at a site in Lancashire.

However, business at the Preston New Road site has had to be repeatedly put on hold by fossil fuel exploration company Cuadrilla due to minor earth tremors.

Under current rules, any earthquake that exceeds the seismic limit of 0.5 must bring drilling to a halt, but industry figures have suggested this limit is too strict.

Now Tom Crotty, an Ineos director, has told The Times he thinks “it would be difficult to see the industry develop successfully with a 0.5 operating limit.”

Ineos is a petrochemicals company led by Jim Ratcliffe, Britain’s richest person, which owns fracking rights for large areas of northern England.

Despite pledging to invest massively in UK fracking, Mr Crotty confirmed the firm was nowhere near extracting fossil fuels using this technique, citing current quake restrictions as a factor.

“We are a long way from getting to that point in our development, probably at least two years away, but 0.5 will be a barrier,” he said.

Cuadrilla, which remains the only company currently engage in UK fracking, has recorded six tremors that exceed the legal limit since it began operating near Blackpool in October.

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Earlier this month it was struck by a magnitude 1.5 event – the largest so far.

Though the company has reported that it successfully extracted some shale gas at the beginning of November, its chief executive Francis Egan has proposed that raising the quake limit to a magnitude of 2 would allow them to operate successfully and safely.

Mr Crotty agreed there was “absolutely no impact at the sorts of levels that have been recorded” at the Lancashire site.

He said while he was not confident the government would heed this advice, the company would continue investing in potential sites as he was confident the UK would one day need shale gas.

“Whether we develop these resources now or whether we sit ... and develop them at some point in the future, we have a very strong belief that these resources will be required,” he said.

“The UK’s level of imports of gas is going up each year and that’s not sustainable.”

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The government has previously stated it is not currently intending to relax seismicity rules, however energy minister Claire Perry has noted they are set at a “cautious” level and indicated they will be reviewed in the future.

Environmental campaigners have expressed strong concerns not only about minor earthquakes linked with fracking, but also the implications of investing in more carbon-emitting fossil fuel technologies.