Rachel Reeves has been warned that cutting cash ISA limits will cost the Treasury billions and will not encourage people to start investing.The Building Society Association (BSA) say the damage inflicted by cutting cash ISA rates would result in up to 60,000 fewer mortgages being offered across the property market, as well as hamper the government’s own target of 1.5 million new homes across the term of parliament.As a result, BSA estimate that damaging economic growth and reducing tax revenues could hit the Treasury by £2.5bn.Over the summer, building societies including Nationwide and Skipton wrote to the chancellor pleading with her to leave cash ISAs untouched.Building societies are among those who offer cash ISA products and use those deposits to support their ability to fund residential mortgages. Cutting the amounts saved into them could hit building society mortgage supply by 5 per cent, says BSA research. They tend to be particularly active in the first-time buyer market.The Treasury select committee chairman Dame Meg Hillier said that it was “not the right time to cut the cash Isa limit”.Currently, rules allow each person to save £20,000 per tax year into ISAs across the available range, which includes Lifetime ISAs as well as cash and investing versions. Speculation has suggested Ms Reeves may cut that by half with regards to how much can be saved as cash, with the remainder of the allowance then able to be diverted towards investing.The chancellor earlier this year highlighted the vast difference in potential returns that saving or investing £2,000 could make, and though eyebrows were raised at the rates used in each case, the essential point remains valid: over prolonged periods of time, investing tends to yield better results than saving.Meanwhile, the results of a new poll show more people would rather potentially pay tax on cash savings than start investing.Get a free fractional share worth up to £100.Capital at risk.Terms and conditions apply.Go to websiteADVERTISEMENTGet a free fractional share worth up to £100.Capital at risk.Terms and conditions apply.Go to websiteADVERTISEMENTThe government have been clear that they want to create a culture of investing across the UK, which has lower numbers of retail investors – the general public, in other words – than other nations such as Germany, Sweden or the US.But the chancellor’s reported plan to effectively herd people into stocks and funds by cutting their tax-free savings allowance has been widely criticised, with most industry experts agreeing it is entirely unlikely to have the desired effect.( More