But they may end up disappointed as “this one may not make into the manifestos,” according to Hargreaves Lansdown.

Almost a third (31%) of investors think a Tory government would be better for their investments, while 27% think Labour would.

Some 23% of people said they don’t know which political party would be better, in the research conducted for Hargreaves Lansdown.

Susannah Streeter, head of money and markets, at Hargreaves, said: “There’s been much discussion as to whether or not Labour will introduce new wealth taxes. Coming on the back of the Conservative’s cuts to the dividend tax and capital gains tax thresholds - both effectively raising wealth taxes – some of this speculation could sound the alarm bell for investors.”

She warned that the rumours shouldn't just raise concerns for the super-rich, but also for people with defined contribution pensions, or those who are putting money away to help protect them later in life.

Conservative planned ISA reforms have so far focused on improved digital reporting which should make it easier to transfer ISAs, as well as the proposed British ISA, where the intention is for there to be an extra £5,000 allowance for investing in UK securities.

Labour has so far put out more forward-looking detail on financial services and the party has not proposed any new wealth taxes at this stage.

The consultation on the British ISA will close on Thursday.

Ms Streeter said: “There’s still a long way to go before a UK-focused tax wrapper would be implemented, and many more discussions to be had on the best ways to encourage UK investment, or indeed whether the ISA regime is the right place for this product.”

She said instead targeted changes to the Lifetime ISA could enable it to provide a more attractive way for self-employed people to save for the long term.

By raising the maximum age for opening and contributing to 55, it would make the Lifetime ISA more relevant to the self-employed, 70% of whom missed out because they were too old when it launched in 2018.

By reducing the penalty for any self-employed LISA holders accessing their pot before age 60 to 20%, it would enable the government to recover their bonus, without imposing a penalty. Ms Streeter said: “It would make the LISA more attractive to this group, who typically have variable cash flow and lack the confidence to put money away for the long term.”

• The research figures come from an Opinium survey of 2,000 people on behalf of Hargreaves Lansdown conducted in April.