Energy giant Ineos has urged the Government to relax the "unworkable" regulations on tremors caused by fracking.
Current rules on the process for extracting shale gas, which involves pumping liquid at high pressure deep underground to fracture rocks and release gas, halt work when seismic activity above 0.5 local magnitude is detected.
Shale firm Cuadrilla, the only company to start fracking in the UK, has been forced to pause operations in Lancashire on a number of occasions when seismic activity above thresholds have occurred.
Ineos, which also hopes to frack for shale gas in the UK, said the 0.5 limit is thousands of times lower than levels set in the US and called for it to be raised.
The company's chairman Sir Jim Ratcliffe said the typical limit in the US of 4.0 magnitude was one the American Environmental Protection Agency "feels is safe and will not lead to any damage to land, property or people".
The 4.0 magnitude limit is 3,162 times higher than the 0.5 limit in the UK, and 177,827 times stronger in terms of energy release, he said.
Of the UK rules, he said:
But ministers have already said they have "no intention of altering" the regulations on tremors caused by fracking.
A letter from Energy and Clean Growth Minister Claire Perry, obtained through a Freedom of Information request by Greenpeace's investigative news team Unearthed, indicates the Government is standing firm on the issue.
Writing to Cuadrilla chief executive Francis Egan late last year after he called for an urgent review of the system, Ms Perry reiterated her backing for shale gas.
But she said the company had not flagged the issue as its hydraulic fracture plan was developed and reviewed with reference to the regulations.
Any shale developments must be safe and environmentally sound, she said, concluding: "The Government believes the current system is fit for purpose and has no intention of altering it."
In response to Ineos calling for the government to weaken safety regulations to make fracking easier, Dr Doug Parr, Chief Scientist for Greenpeace UK, said: