Liz Truss is set to tear up Tory promises on fracking safety after scientists admitted they don't know if it will cause earthquakes.
The government has been accused of lacking integrity over the decision to plough ahead regardless, with drilling licences expected to be issued next week for the first time in three years.
It flies in the face of the government's 2019 pledge that a ban on fracking would not be lifted until it could be "categorically" proved that it does not cause tremors.
A leaked study by the British Geological Survey (BGS) reportedly says experts are still unable to do this - stating there are still “significant existing knowledge gaps”.
Ms Truss has signalled her support for fracking, telling the House of Commons last week that she intends to "end the moratorium on extracting our huge reserves of shale”.
The ban on fracking - which is a a drilling technique used to release gasses from under the surface - was put in place following a series of earthquakes.
One measured 2.9 on the Richter scale and caused property damage across Blackpool, prompting an investigation by regulators.
Responding to the leaked BGS report, Dr Doug Parr, chief scientist for Greenpeace UK, said: "The broad lesson from this report is there have been no significant breakthroughs in the science of prediction and management of earthquakes caused by fracking.
"For the Truss government to reverse its position on shale gas on the back of this would simply be breaking a clear promise on which they were elected.
"They have no mandate from the voters or from the circumstances for such a change, and if they carry it through it would just mean we had an industry with lower standards of safety, and a government with lower standards of integrity."
Friends of the Earth energy campaigner, Danny Gross, said: "If the government caves in to lobbying by fracking companies to water down existing earthquake regulations it will further undermine public confidence in this industry.
“Fracking will only have a negligible impact, if any, on soaring fuel bills. Ministers should abandon shale gas extraction and focus instead on energy efficiency and onshore wind and solar – which are cheap, popular and quick to build.”
The BGS report's release has been delayed following the Queen's death, and today the government refused to confirm its contents.
However a copy leaked to The Guardian suggests there is still more work to be done in understanding the impact of the process.
Scientists said that forecasting earthquakes caused by fracking and predicting their magnitude “remains a scientific challenge”.
The report was commissioned by current Chancellor Kwasi Kwarteng in April, when he was business secretary under Boris Johnson.
It said problems remain with identifying possible sites that might be able to handle earthquakes with a magnitude of 3.0.
The BGS added that the low number of fracking sites in the UK make it “difficult to make a valid comparison” with other countries.
The Department for Business, Energy & Industrial Strategy (BEIS) declined to confirm the contents of the report.
A government spokesperson said: “We commissioned the British Geological Survey to advise on the latest scientific evidence on shale gas extraction.
“Making the most of our own gas resources makes us less dependent on imports and helps maintain the security of the UK’s energy supply in both the short and long-term.
"Drawing on lessons from around the world, we will make sure it is done as safely as possible and where there is local support.”
A BGS spokesperson said: "We cannot comment on the report until it has been published by BEIS."
