“He has no democratic mandate… An early election? Bring it on!” These bullish words, written in 2007, were from our own Prime Minister Theresa May. So what has changed May’s view of unelected prime ministers?

Previously May seems to have deemed it a necessity for the country to have its say on Gordon Brown’s premiership, when he took over from Tony Blair in an unchallenged Labour leadership election in 2007. While the times were different, and the political pressures of the day on our prime minister are exceptional, the essential argument that May laid out stands the test of time. How can the current government expect to be able to follow its chosen course without an explicit vote of confidence from the British people?

Philip Hammond’s Budget U-turn over National Insurance contributions illustrated the problems of attempting to govern on a new policy platform, and the practical impossibilities of enacting any changes with such a small majority in parliament.

Theresa May is clearly and successfully charting a different course from that of the Cameron-Osborne era of government. TYet pursuing such a change in course is antithetical to her position as an unelected prime minister.

The re-introduction of grammar schools, changes to National Insurance contributions for the self-employed and the pursuit of an over-arching Industrial Strategy are just a few of the policy areas in which Theresa May has sought to create a new government in her own image. Instead of the “Big Society” and the social and economic liberalism that characterised David Cameron’s view of the world, we now have May’s new social and economic settlement.

This ideology, moves away from the economically liberal instincts of the previous government, and instead focuses on a model of increased state intervention tinged with patriotism, with a pivot away from unrestricted market forces and globalisation. She seems to be holding, as Oliver Letwin put it, a socio-centric instead of an econo-centric world view.

While this is proving a successful and popular interpretation of the mood of the country, with May’s polling sky-high, the sustainability of pursuing this new course is waning. Changes to NICs by Philip Hammond articulated the constant struggle of governing without electoral legitimacy. Reneging on a manifesto pledge made at the 2015 election, regardless the viability of the new policy proposed, shows the lack of flexibility that Theresa May has in embarking on her own model of governance. For her to be able to define and promote Mayism, her manifesto must be put to the electorate. Without this, we will be stuck in the middle of continuity Cameron and Mayism-lite.

Moreover, with the Great Repeal White Paper set to be published, and the government likely to tweak various EU legislations in order to fit the UK statute books better, the need for a personal mandate has never been more acute.

May’s desire to pursue the change in the legislative agenda poses questions of legitimacy. She is unable to break definitively from the manifesto which won the Conservatives a comprehensive majority in 2015. That contract with the voters cannot wholeheartedly be abandoned as a result of Brexit, in spite of the new challenges that face the country. Without express approval form the voters, manifesto pledges need to be treated as a point from which policy cannot depart.

Along with this, the looming fights over the Great Repeal Bill and the overall Brexit deal will become more of an issue without a renewed democratic mandate for May. How can the government possibly secure a Brexit deal acceptable to the House of Commons and the wider public if it could not pass a relatively small tax rise when riding between 15 and 19 points ahead in the polls?

This political impediment will not go away, and has been illustrated throughout history. Look at the Labour party. Both Gordon Brown and James Callaghan have shown us that unelected prime ministers struggle for political legitimacy. Brown inherited a strong majority and relative popularity in 2007. His failure to call an election in 2007, morphing into “bottler Brown”, irreparably harmed his public standing. May has on more than one occasion been compared to the former Labour man, with a similarly centralised style of decision-making. If the economy takes a nosedive at any point, mirroring the 2008 recession, she could be the eventual electoral casualty just like Brown was. Even with the opposition so weak, the long-term effects of enacting change without a mandate could taint her as indecisive and illegitimate.

James Callaghan similarly went down that route when he succeeded Harold Wilson in 1976. At the time, Callaghan decided against calling an election against Margaret Thatcher, who derided him for lacking the electoral courage. The reputations of neither Brown and Callaghan have recovered, and Theresa May would do well to avoid those mistakes, for the sake of her own legacy and policy programme.

Instinctively the public does not appreciate having an unelected prime minister, and the novelty of May’s perceived stability cannot hold for too long. With a commanding lead in the polls, Mayism must now be put to the people.