Mr Rees-Mogg, the former Brexit opportunities and efficiency minister, has been given a significant promotion to business secretary in the new prime minister’s first cabinet.
The PM’s official spokesperson said the mission of hunting out Brexit opportunities would now be “taken across departments”.
Handed the role by Boris Johnson in February, Mr Rees-Mogg spent six months trying to interest his colleagues in ditching EU regulations and launching attacks on the civil service over working from home.
His office listed scrapping Brussels-era regulations on vacuum cleaners as one of the “most interesting” ways to capitalise on the UK’s Brexit “freedoms” after asking tabloid readers for ideas.
However, Mr Rees-Mogg did succeed in putting EU rules and regulations on the agenda for the recent Tory leader battle between Ms Truss and rival Rishi Sunak.
Ms Truss promised to ditch thousands of EU laws remaining on the UK statute books by the end of 2023 – despite warnings of “chaos” and disruption from lawyers, business leaders and union bosses.
Green campaigners have reacted angrily to the appointment of Mr Rees-Mogg as business and energy secretary, where he will also now be in charge of the climate brief.
Mr Rees-Mogg has previously played down the earthquake risk of fracking and stressed the need for oil firms to be able to keep their profits and drill more “so they get every last drop out of the North Sea”.
He has also warned against “climate alarmism” and said he wants his constituents to have cheap energy “rather more than I would like them to have windmills”.
Scotland’s first minister and SNP leader Nicola Sturgeon also questioned Ms Truss’s decision to give Mr Rees-Mogg such a crucial role.
“Any prime minister that puts Jacob Rees-Mogg in charge of energy – and therefore, by definition, in charge of some of the big decisions that will guide the UK’s response to tackling the climate emergency – has to have a big question mark over her judgment.”
His appointment to the Department for Business, Energy and Industrial Strategy (Beis) comes as Britons face crippling energy bills caused by sky-high gas prices in the wake of Russia’s invasion of Ukraine.
The PM, chancellor Kwasi Kwarteng and Mr Rees-Mogg have been working to finalise a multi-billion package to freeze household gas and electricity bills, with some estimates that the package could cost more than £100bn.
A government source confirmed that the plan is to freeze annual household energy bills around the £2,500 mark. It is based on the current £1,971 cap – plus the £400 universal handout announced under Boris Johnson’s government.
Ms Truss is expected to set out her plan as she opens a general debate on UK energy costs on Thursday, and Mr Rees-Mogg will close it.