Opening the EU debate again is clearly a political minefield. But we have to do it | Simon Jenkins

Andy Burnham must tread cautiously, but Brexit was a very grave act of self-harm – and he is right to address it

Andy Burnham’s opening debate on whether Britain should rejoin the EU is divisive, painful and politically risky. That is why it should be welcomed. To jeopardise his popularity so soon after coming to office might seem reckless, but the issue is urgent and not going away. Brexit is continuing to damage the nation’s economy. The prime minister’s job is to challenge, if not reform it.

The Brexit decade has evoked a bizarre sense of guilt among Britons. Opinion polls show nearly 60% regard it as a mistake, with just a third still in favour. Almost a quarter of those who voted for Brexit now regret it. While early forecasts of economic disaster were proved wrong, the accumulated cost of cutting links with Britain’s biggest trading partner is estimated at 6-8% of GDP.

Simon Jenkins is a Guardian columnist