John Healey called Britain’s banks the “jewel” in the economic crown on Thursday. Within hours, the City was braced for a tax raid. The Chancellor is reportedly preparing to raise the bank surcharge from 3pc to 8pc in his 28 October Budget to help fund pre-Budget giveaways. Banks warn the move could cost the economy up to £20bn over a decade. Great British PAC is concerned that a raid on the sector the Chancellor himself calls central to growth will not repair the public finances, and that the bill may land on the households and small firms that depend on bank lending.