A strong supporter of Liz Truss to win the race for No 10, the arch-Brexiteer called for “a re-thinking of the British state” – arguing mere cuts in public spending will not go far enough.
The Leave campaign won the 2016 campaign partly on a promise to boost spending, notably by £350m-a-week on the NHS, but Mr Rees-Mogg is pointing to a different agenda.
“Our departure from the European Union necessitates a re-thinking of the British state,” the minister for Brexit opportunities has written in a newspaper article.
“This means going beyond ministers looking for fiscal trims and haircuts and considering whether the state should deliver certain functions at all.”
It comes after Ms Truss vowed to press the accelerator on ripping up thousands of EU regulations if she wins power, which has raised fears that protections will disappear.
The Liberal Democrats said the comments would “raise fears that the worst damage to relations with our neighbours is not yet done”.
Mr Rees-Mogg argued tearing back the state’s role would allow the next government to help people with rocketing energy bills, which the leadership race favourite has said she will do through tax cuts.
“As a supporter of Liz Truss to become prime minister I am a strong advocate of the benefit of tax cuts to the economy and to the British consumer,” he wrote in The Daily Telegraph.
The call was endorsed by another senior Truss backer, former Brexit minister David Frost, who is expected to be given a leading role in her administration.
Mr Rees-Mogg was “absolutely right about the need to "rethink the British state" after Brexit”, Lord Frost said.
Layla Moran, the Lib Dem foreign affairs spokeswoman, said: “Rather than try to dismantle the British state, maybe Rees-Mogg should try and tear down the huge amounts of red tape which have been erected thanks to the Conservatives’ trade deal with Europe.”
The Best for Britain better democracy campaign group seized on Mr Mogg claiming £4bn had been found from his efficient drive – arguing it was too little to avoid dramatic cuts.
“It will likely lead to the civil service to stop delivering functions including essential public services that Tory governments continue to run into the ground,” said Naomi Smith, its chief executive.
The call comes after the respected Institute for Fiscal Studies warned that big spending cuts are inevitable if Ms Truss pursues the £30bn-plus of tax cuts she plans, calling them unrealistic.
Angela Rayner, Labour’s deputy leader, said: “There’s nothing ‘efficient’ about cutting frontline services already overwhelmed by backlogs when families are already struggling to make ends meet.
“Now Liz Truss is pledging yet more cuts which will only worsen the backlogs we already have in courts, airports and GPs, leaving people waiting even longer for passports, driving licences, and vital appointments.”