Britain's public finances are losing around £330 billion ($442 billion) a year due to weak ​economic growth, population ageing and ill health, ‌according to estimates from a think tank that show the scale of the challenge facing the next prime ​minister.

The left-leaning Resolution Foundation said former Manchester ​mayor Andy Burnham, who is due to ⁠replace Keir Starmer in Downing Street on Monday, ​needs a new fiscal strategy to stop borrowing, ​public spending cuts and tax increases from becoming more painful.

About two-thirds of the £330 billion hole comes from ​a slowdown in economic growth per person since ​2007, it said.

In a report into what it called Britain's ‌two-decade ⁠fiscal funk, the Resolution Foundation also said:

• the triple lock system for increasing the value of state pensions should be replaced with a less ​expensive link to ​average earnings ⁠alone
• reforms are needed to replace fuel duty receipts which are being ​lost as drivers switch to electric cars
• increased ​investment in public services would counter a drop-off in productivity
• the impact of the Iran war has probably ⁠reduced ​the government's headroom against the ​current fiscal rules from £23.6 billion in March to £10 billion now.