Michael Gove has dramatically expanded his Whitehall empire, emerging as the biggest winner of Boris Johnson's Cabinet reshuffle.

       The full scale of the former Cabinet Office minister's new domain became clear on Saturday night as Downing Street announced the appointment of Andy Haldane, the former Bank of England chief economist, as a new permanent secretary in Mr Gove's former department.

       Unusually, Mr Haldane will report jointly to the Prime Minister and Mr Gove, despite the Prime Minister's ambitious former leadership rival now leading a separate, rebranded Department for Levelling Up, Housing and Communities.

       Mr Gove will also, said No 10, said "drive cross-Whitehall efforts to deliver a programme of tangible improvements in every part of the UK", effectively giving him jurisdiction for the levelling-up agenda across government.

       He has also been handed the additional title of minister for intergovernmental relations, which will see him continue to lead talks with the Welsh, Northern Irish and Scottish administrations on Mr Johnson's behalf, despite the Prime Minister remaining minister for the union.

       Mr Gove is now likely to lock horns with the Treasury as he seeks to carve out a billions of pounds in funding for the levelling up agenda in Rishi Sunak's autumn spending review.

       Mr Gove will oversee the publication of a Levelling Up white paper setting out policies intended to "improve livelihoods, spread opportunity and drive economic growth."

       A 'colossus of a department'

       A senior Government source described Mr Gove's new role as an "underpriced move of the reshuffle", following claims that he had been demoted.

       "It's a colossus of a department," the source said of the new levelling up department.

       Mr Johnson has also allowed Mr Gove to retain responsibility for policy relating to elections and the Union, two key areas which formed part of his portfolio at the Cabinet Office.

       News of Mr Gove's expansive brief comes after Mr Johnson appointed Dominic Raab as Deputy Prime Minister amid tense talks about the former foreign secretary's move to run the Ministry of Justice.

       Separately, an ally of the Prime Minister suggested that Nadine Dorries had been appointed as Culture Secretary as part of efforts to help the Government to communicate with the public. Ms Dorries is a novelist whose books have sold more than 2.5 million copies.

       "Very few people can communicate as clearly as her," the ally said. "She says things as she sees them. That's a priceless quality. And 2.5 million readers cannot be wrong."

       Meanwhile, Priti Patel, the Home Secretary, was understood to be preparing to "double down" on a series of controversial policies, including a crackdown on small boats crossing the Channel, after Mr Johnson endorsed her approach during her reappointment meeting in No 10.

       On Saturday night, Downing Street announced that the housing department will be renamed the Department for Levelling Up, Housing and Communities, following the departure of Robert Jenrick in Wednesday's reshuffle.

       At the Cabinet Office, Mr Gove's formal title was Chancellor of the Duchy of Lancaster, a role now taken over by Steve Barclay, the former chief secretary to the Treasury. Strengthening the union and constitutional issues, including elections, formed two of the nine responsibilities of the role listed on the gov.uk website on Saturday night.

       Mr Gove, now the Secretary of State for Levelling Up, said: "I’m thrilled that the PM has asked me to lead the Levelling Up agenda, the defining mission of this Government ... We have a unique opportunity to make a real difference to people’s lives.”

       On Saturday night a poll by Opinium showed that more people still oppose the Government's social care plan, which includes hiking National Insurance payments, than support it. The survey of 2,000 adults found that 36 per cent backed the policy compared to 41 per cent who opposed it.