UK fracking rules on earthquakes could be relaxed, says minister

Exclusive: Claire Perry says level at which operations must be halted could be raised

Rules designed to halt fracking operations if they trigger minor earthquakes could be relaxed as the shale industry begins to expand, the UK energy minister, Claire Perry, has said.

A series of small tremors seven years ago prompted tough regulations that mean even very low levels of seismic activity now require companies to suspend fracking.