More than half (52.6 per cent) of respondents believe that taxes will increase and a further 43.5 per cent believe that they will probably increase, the research shows. 

Burnham’s bid to become Labour leader and prime minister has been backed by 349 of the party’s 403 MPs, which means that he is set to become prime minister on 20 July. It is now impossible for a rival to run against him.

“Mr Burnham will inherit one of the toughest fiscal challenges of any incoming Prime Minister in decades. With pressure to repair the public finances, fund public services and stimulate economic growth, investors believe that meeting those competing priorities is likely to require higher taxes,” Susannah Streeter, chief investment strategist at Wealth Club, said in a note.

“Perhaps the most revealing finding is what investors now see as the biggest risk to their wealth. Nearly 45 per cent say higher taxes are their greatest concern, making them by far the biggest perceived threat,” she continued. “By comparison, just 3.5 per cent cite inflation and the same proportion identify market volatility. That represents a significant shift in investor sentiment, with taxation now eclipsing many of the economic concerns that have dominated headlines in recent years.”

“Investors will understandably be looking for reassurance that any changes to the tax system support long-term economic growth, encourage investment and provide certainty for businesses and households,” Streeter said. “Many will be concerned that a heavier tax burden could weaken incentives to invest, save and grow businesses, potentially weighing on economic confidence at a time when the UK needs stronger private sector investment. Providing greater clarity over the future direction of tax policy will be just as important as delivering economic growth if the new government is to maintain confidence among businesses and investors.”

With expectations of further tax rises running so high, Streeter believes that now is the time to review financial plans, make full use of available tax allowances and ensure that investments are structured as tax-efficiently as possible before any future changes are announced.

Meanwhile, Mark Campbell, head of wealth planning at , highlighted recent speculation that a future Andy Burnham government could align capital gains tax (CGT) rates with income tax. This has prompted some investors and business owners to consider bringing forward asset sales before any potential changes. “While no formal policy has been announced, the rumours have once again highlighted how uncertainty alone can shape taxpayer behaviour,” Campbell said in a note.

"We also need to remember that capital gains tax is, to a large extent, voluntary. Individuals must only pay it when choosing to dispose of an asset. Push rates too high and there is a real risk that individuals defer disposals, reducing transactions, slowing investment and potentially generating less tax than expected,” Campbell continued. "Any reform of CGT must strike the right balance. While raising revenue is important, so too is maintaining incentives for investment, entrepreneurship and economic growth. Tax policy should encourage sensible long-term decision-making, not drive behaviours based on political speculation.”

Mark Haefele, chief investment officer at , highlighted that investors will be looking for further reassurance from his cabinet choices and policy agenda, but he continues to see selective opportunities in UK assets. He thinks that fiscal restraint should limit both additional gilt supply and the need for tighter monetary policy, supporting opportunities in short- to medium-duration quality bonds. Sterling should remain well-supported, particularly against the Swiss franc, given its attractive relative yield. With about 75-80 per cent of FTSE 100 revenue generated outside the UK, the broader equity market should remain relatively insulated from domestic political change.

“We remain focused on selective opportunities in UK assets, including short- to medium-duration quality sterling bonds and favorable sterling carry trades, while maintaining a neutral view on UK equities within globally diversified portfolios. Burnham’s commitment to the existing fiscal framework should limit both the risk of a destabilizing rise in gilt issuance and the likelihood that fiscal policy forces the Bank of England to tighten more aggressively," Haefele said.

The investor survey, conducted by the Bristol-headquartered investment service for high net worth and sophisticated investors, was carried out on 6 July 2026.