Fracking has been halted at the Preston New Road site in Blackpool after the largest earthquake yet was detected.
A tremor with a magnitude of 1.55 shook the ground last night, leading to the site being closed down while tests are carried out.
The previous strongest quake was 1.5 at Little Plumpton.
Anything above 0.5 means fracking must be stopped.
The Preston New Road site has been at the centre of the angry debate over fracking after two earthquakes in 2011 forced the practice to stop.
Cuadrilla, the firm behind the site, said that the tremor would not have been felt by most people and said it was the equivalent of ‘a large bag of shopping dropping on the floor’.
Fracking, or Hydraulic Fracturing, involves pumping vast quantities of water and chemicals into unstable rock to release combustible gas.
More than 100 licences have been awarded by the government, allowing firms to pursue a range of oil and gas exploration activities in certain areas.
Since the 2011 earthquakes, local residents and environmental campaigners have been fighting Cuadrilla’s plan to restart their Lancashire operations.
The local council had also been opposed to the plan but the government forced permission through.