After spending months trying to dodge an embarrassing defeat in the Commons on cutting international aid, the government sprang a last-minute vote and announced details of a “compromise” with 14 sceptical Tories. What happened? With Boris Johnson having a majority of 80 in parliament, the rebels’ ringleader, Andrew Mitchell, the former international development secretary, needed about 40 Conservatives to join him to scupper the government’s plan. After personal lobbying, Johnson and the chancellor, Rishi Sunak, managed to sway a small but significant number of waverers who voted with the government. Despite attempts to force a vote on the issue in the past, there had been no formal declaration where MPs were forced to show their hand, so the number of rebels remained a mystery until the formal division. In the end, the government won comfortably by 333 votes to 298, with just 25 Tories rebelling. They included the former prime minister Theresa May and ex-cabinet members including Jeremy Hunt, Karen Bradley and David Davis. What was the Treasury’s compromise? Ministers knew they were in a bind given proponents of keeping international aid spending at 0.7% of gross national income said the government would be breaking the law – and a manifesto commitment – by cutting it to 0.5% indefinitely, equal to around £4bn every year. Sunak argued publicly that the cut was only temporary and was needed to help begin finding a way to pay for the huge financial costs of Covid, but he refused to put a date on restoring aid spending to its normal levels, saying only that it would return “once the fiscal situation allows”. In an attempt to win over Tories who thought it was a shady move to try to get away from 0.7% more permanently, on the eve of the vote the Treasury set out the two conditions under which the spending would rise again. Sunak passed the buck to the Office for Budget Responsibility (OBR), set up by George Osborne in 2010 to provide independent economic analysis and advice to the government of the day. He said 0.7% would return when the OBR’s fiscal forecast confirms that “on a sustainable basis” the UK is not borrowing for day-to-day spending and that underlying debt is falling. The chancellor suggested there could be further tax rises and spending cuts if MPs rejected his plan. How did the government pull off a win? Tory whips breathed a big sigh of relief that they had quietly managed to broker a deal ensuring 14 previously hesitant backbenchers would vote for Sunak’s proposal, including the former cabinet minister Andrea Leadsom. Some Conservative insiders said it was unlikely the government would have called the vote if it thought it was going to lose, though it was still a gamble. However, given that the exact number of prospective Tory rebels had never been known – estimates ranged up to about 50 – the government still had reason to worry. Since the “compromise” and vote were announced with less than 24 hours’ notice, some Conservatives were feeling confident their colleagues would not be easily swung. They thought that the two conditions for 0.7% to be reinstated were unlikely to be met in this parliament – ie within three years. The Tory peer Liz Sugg said that only once in the last 20 years had the two conditions been met, so it was unlikely 0.7% would return any time soon.