Rachel Reeves has been warned by top economists that she faces an “impossible trilemma” ahead of the autumn budget and must raise taxes or tear up her flagship borrowing rules to fill a £41bn black hole left by Labour U-turns, higher borrowing and sluggish economic growth. The National Institute of Economic and Social Research (NIESR) – a leading economic think tank – said the chancellor could also look at spending cuts as a way to raise the money needed by 2029-30 to remedy a £41.2bn shortfall on her “stability rule”. But ministers have already squeezed significant savings out of their departments in cuts that were unveiled at last month’s spending review, meaning there is now a mounting expectation that the chancellor will be forced to raise taxes instead. In the wake of the warnings, there are growing questions over how the government will raise the money to fill the gap in the public finances, given Labour’s manifesto pledge not to raise taxes on “working people” leaves the chancellor with a limited number of workable options. Here, The Independent takes a look at a number of tax rises that the government could rely on to raise funds and balance the books. Tax threshold freezes The Treasury’s most likely move would be to extend the freeze on income tax thresholds. This means that as wages rise with inflation, over the years workers are dragged into higher tax bands and end up paying more. A freeze on the threshold at which the higher 45 per cent tax rate is paid was one of the options suggested by Ms Rayner in her leaked memo. But there is growing speculation the government could extend the freeze across all tax brackets. Sir Keir has left the door open for such a move, refusing to rule it out when pressed on it at PMQs last month. While he gave an unequivocal answer ruling out increasing VAT, income tax or national insurance, he refused to do so when it came to tax threshold freezes. It’s a stealth tax, the impacts of which are not felt immediately, meaning it is normally better received among the general public compared with a direct hit to businesses or pay slips. But, if the freeze were extended to the end of the parliament, it could also bring in billions for the Treasury as earnings rise. The freeze, which is already planned to last until 2028, is expected to drag around two million workers into higher tax bands.Wealth tax There have been calls from Labour MPs on the left of the party to introduce a wealth tax, calls which have only grown in the wake of the government’s £5bn welfare U-turn. Rachael Maskell, the architect of the rebellion which forced the government into shelving key pillars of the bill, demanded the government increase taxes on the very richest to pay for the climbdown. Piling even more pressure on the Treasury last month, former Labour shadow chancellor Anneliese Dodds also urged the Treasury should consider such a tax. Former shadow chancellor Anneliese Dodds is among those who have urged the government to consider a wealth tax More