A crisis of legitimacy looms over the British political landscape. Confidence in our governing institutions is under severe stress. Living standards have eroded rapidly following the Great Recession as the cost of living increased. The sense continues to grow that no matter what we do or who we vote for, these trends will continue, and life will worsen.

These trends strike at the two pillars upholding public confidence in our governing institutions and in democracy itself: input legitimacy, the extent to which we feel that we are empowered to shape the policies of government, and output legitimacy, the quality of the results government gets. Both are necessary foundations of the legitimacy of our governing institutions. Both are under threat, and tackling that threat will be the next government’s greatest challenge.

Research released by King’s College London last year showed that the proportion of Britons who have confidence in the Westminster Parliament had fallen from 46% in 1990 to just 23%. Just 24% of Britons had confidence in the government, meaning the UK ranked in the bottom third among countries they surveyed.

If Scotland were ranked independently, we would have come ahead of only Mexico, embroiled in civil conflict, and Greece after a decade of enforced austerity, IMF bailouts and attendant political crises.

Forget social media chatter about support – or lack thereof – for abolishing Holyrood in light of The Sunday Times’ most recent polling by Nortstat. Britons entirely lack faith in our governing institutions, and Scottish attitudes represent merely the sharp edge of that sentiment.

Crises of legitimacy for governing institutions are breeding grounds for outsider politics of all stripes. It is no accident that those with the lowest incomes were the most likely to vote for independence in 2014 and leave the EU in 2016. Those with less to show for living under current governing arrangements are inevitably more likely to favour tearing up those arrangements even if the alternative is unclear.

But it is not just the worst off in British society who are today attracted by outsider politics and populism. The UK came fifth out of 28 countries ranked by strength of populist sentiment in the most recent Broken-System Index from Ipsos, and we were one of just three countries in which such sentiment had become stronger since 2019. The results suggested that half of us believe that we need a strong leader willing to break the rules to fix the UK and that most of us believe the economy is rigged in favour of the rich and powerful and want a strong leader to retake control. Sound familiar?

If solving the UK’s legitimacy crisis and stemming the rising tide of populism was merely a case of swapping Rishi Sunak’s Conservatives for Sir Keir Starmer’s Labour, we would have little cause to worry about the future of British democracy in light of Labour’s stonking poll lead. But it isn’t.

As the 19th-century giant of Dutch liberalism, Johan Thorbecke, put it, “Trust arrives on foot and leaves on horseback.” Rebuilding Notre Dame takes far longer than it took for fire to destroy its spire.

Rebuilding confidence in British governing institutions will not be easy. It will take time and require serious action to re-establish both input and output legitimacy. British democracy requires reinvigoration to re-establish faith that the government acts in the people’s best interests and can respond to their demands. The British economy equally requires both an injection of energy and investment in resilience if living standards are to improve and be protected.

As the general election approaches, what hope I had that Labour could grasp these thorny challenges firmly is diminishing. Sir Keir and his Shadow Chancellor, Rachel Reeves, appear more concerned with sticking to arbitrary fiscal rules inherited from the Conservatives than building a resilient and thriving economy. Their emphasis on growth before investment seems to put the cart before the horse.

Sir Keir rejected the notion of electoral reforms that might give voters the sense that their vote matters long ago. The idea of abolishing the House of Lords and replacing it with a democratic revising chamber – a singular achievement that would have dramatically strengthened British democracy and bound the nations closer to the Union – is confirmed to have been ditched.

If Labour’s prospectus really is what lies before us now, it is not enough. Labour outriders tell us this paucity of ambition is a necessary aspect of their election strategy, that you cannot affect change without winning the election first.

But what mandate would a Labour government have to take the action necessary to address the UK’s legitimacy crisis if it goes into an election promising only tinkering? And what incentive will they have to ramp up their ambitions mid-term if their policymaking is grounded in their electoral strategy and not vice-versa? After all, there is always another election coming.

Never mind asking what the point of ambitious and radical policies is if you lose – what is the point of winning if you have not equipped yourself to succeed in the crucial task of governing?

Sir Keir recently said that, rather than being about legislation, his first 100 days in power would be about a “change in mindset” and “setting the relationship”, changing the “feel” of government. This is the least ambitious agenda he could set.

The Starmerites are keen on learning the lessons of New Labour’s successes in campaigning. Perhaps they might reflect on the lessons of their successes in governing.

Tony Blair’s Chief of Staff, Jonathan Powell, wrote that upon taking power, a new Prime Minister has no choice but to “be bold in his first few weeks so that he can reap the benefits of his actions.” He observes that while you might disappoint half your supporters by your actions, if you do not act, “you will soon have disappointed all of them.”

Fail to show the necessary ambition to tackle the UK’s legitimacy crisis, and the trends threatening British democracy will intensify. Populism will continue to thrive, and the Conservatives he ejects from power will be back in five years, selling the snake oil policies that have defeated mainstream governments across Europe.

Sir Keir will either rise to the challenge of rescuing the UK from populism or become its victim. He must show the ambition needed to meet the moment.