Shale firm Cuadrilla has called for the relaxation of the rules, which have forced the company to pause fracking in Lancashire on a number of occasions when seismic activity above thresholds in the “traffic light system” have occurred. But a letter from Energy and Clean Growth Minister Claire Perry indicates the Government is standing firm on the regulations. Writing to Cuadrilla boss Francis Egan after he called for an urgent review of the system which halts work when tremors above 0.5 local magnitude are detected, Ms Perry reiterated her backing for shale gas. But she wrote: “While I hope the industry can thrive in the years ahead, I have always been clear that any shale developments must be safe and environmentally sound.” She said the company’s fracking plan was developed and reviewed over several months with reference to existing regulations “and at no point did you communicate that it would not be possible to proceed without a change in regulations”. She concluded: “The Government believes the current system is fit for purpose and has no intention of altering it.” A number of tremors have been detected that breach the threshold since the controversial process began at Preston New Road, Little Plumpton, on October 15. In December, a 1.5 local magnitude quake was recorded which was reportedly felt in Blackpool. Dr Doug Parr, chief scientist for Greenpeace UK, said: “Despite the minister’s warm words about fracking’s potential, the message this letter delivers is that there’s a limit to the unpopularity the Government is willing to court to sort out Cuadrilla’s problems.” He called for ministers to reverse their support for shale and speed up a clean energy infrastructure programme for the UK. Cuadrilla said: “We have worked within the system during recent hydraulic fracturing at Preston New Road and as a result have a unique data set of information and operating experience. “We are now flow-testing the well that has been fractured and are continuing operations as planned.”