Business leaders are urging Andy Burnham to set Britain on a path to rejoining the European Union if he becomes prime minister.

The former Greater Manchester mayor, who claimed victory in Friday’s Makerfield by-election, has spent the weekend drawing up plans for power as he positions himself to challenge Sir Keir Starmer for the keys to No 10.

With an ambitious list of promises already taking shape – from raising the income tax personal allowance threshold to a major hike in defence spending – Burnham will have to find the money to pay for it.

As Britain prepares to mark the 10th anniversary of the EU referendum on Tuesday, campaigners, economists and business leaders argue the only way to generate growth on the scale required to deliver on changes that voters want is to rejoin the bloc.

Reversing Brexit could deliver £92bn