George Osborne spoke yesterday at a session of the “Treasury and Economic History since 1945” course, taught by my colleague Jon Davis and my fellow visiting professor, Nick Macpherson, at King’s College, London.

Lord Macpherson was Osborne’s permanent secretary – his most senior civil servant – for all his time as Chancellor of the Exchequer until a few months before the end. “It all went wrong when I left,” said Lord Macpherson.

Osborne spoke about the important relationships for a chancellor: those with the Prime Minister, the Cabinet, MPs generally, the civil service, the Bank of England and the British people. He said several times that his relationship with David Cameron was unusual because it was so close. “We worked as a team: I ran his leadership campaign, we worked for five years to change the party, and I ran the 2010 election campaign.”

He took questions from the MA students on the course, including one who asked if a History degree was a good qualification for running the Treasury. Osborne pointed out that the last academic economists to be chancellor were Hugh Dalton and Hugh Gaitskell in the 1940s and 1950s.

He said that much of the job was about political judgement, and launched into a defence of politics, “which has a bad name”, as the means by which 60m people are able to live peacefully on these islands. He said that 80 per cent of the decisions he took as Chancellor were decisions that would be made by any minister, Labour or Conservative. A further 10 per cent were decisions that any Conservative minister would make. It was the last 10 per cent of decisions that were his own and in which he hoped to leave his mark.

He claimed to have reintroduced the word “austerity” to British politics when in 2008, as shadow chancellor, he referred to The Age of Austerity, a 1963 study of the postwar period. “At the time it was a positive thing,” reflecting the consensus – especially strong in the Treasury – that the level of public borrowing after the banking crisis was unsustainable.

Still on the theme of history, he said that the parallels between the post-2008 recession and the banking crisis of the 1870s, which was followed by a decade of stagnant incomes, were too little known.

He refused to be drawn on Brexit-related questions, apart from saying, “I hope I’m wrong”, about his warnings of the economic cost of leaving the EU during the referendum campaign. But he did offer an aside when William Keegan, another visiting professor, suggested that the UK sticks to EU rules while France ignores them when it finds them inconvenient. That was a common view, said Osborne, when he was in his first political job, as a special adviser in the Ministry of Agriculture, Fisheries and Food (“despite being brought up in Bayswater,” he said). “We conducted an audit and found that the UK was not the worst offender, but it was not the best either.”

He was later asked why, as a centrist and an admirer of Tony Blair, he didn’t join the Labour Party. He said he had always been put off by the link with the trade unions, which had recently meant that Unite controls who the party leader is, and had allowed an influx of anarchists and ultra-greens as members. But he added that he thought it was “not a healthy thing” that the Labour Party was in its current feeble state.