In November a group of City figures, including former pensions minister Baroness Altmann and the bosses of high-profile investment groups such as Panmure Gordon and Shore Capital, wrote to the Chancellor pushing for the introduction of a so-called Great British Isa.
They said it would “drive interest from a wider pool of investors and create a multiplier effect, reviving interest in raising equity in the UK, driving economic growth, spreading prosperity and boosting tax revenues”.
Baroness Altmann said: “Brexit was supposed to be about boosting Britain and it is hard to see how encouraging pension funds and Isa investors to invest overseas instead of the UK is the way most taxpayers want their funds spent.
“If Isa investors don’t invest in Britain, then the Government will have to do it and the economy will be weaker. We are in danger of losing our financial position [without investing in UK stocks].”
Around £67bn is currently invested in 11.8 million Isas across the country. According to HM Revenue and Customs, the value of funds held in stocks and shares Isas increased 14pc during 2021-22.
In the November Autumn Statement, the Chancellor announced that from April savers will be allowed to open multiple Isas of the same type in a single tax year without losing their £20,000 allowance.
A spokesman for the Government said: “We don’t comment on speculation about Budget measures.
“We are already making changes to simplify Isas and provide more choice, meaning it will be easier for people to choose the best Isa accounts for their needs and move money between them.”