Andy Burnham’s absent economic advisers are a warning sign for UK investors, according to one of the world’s largest independent financial advisory organisations.

Nigel Green, chief executive at deVere Group, made the remarks following reports that Lord Jim O’Neill turned down a role within government over Mr Burnham’s failure to rule out potential wealth taxes and Lord O’Neill’s opposition to them. The lord is reported to have also wanted to retain oversight of his shareholdings in financial groups and business interests.

Mr Green said: “None have taken a formal role. An Autumn Budget date has already been set. A government cannot promise financial credibility on the back of three respected economists and then fail to bring a single one of them through the door.

“Investors were told this. They believed it. Right now, it simply does not appear true. I doubt this is indecision. It’s a direct response to a policy question Mr Burnham has had every opportunity to answer and has chosen not to. This silence is not accidental, and it’s not free.”

Mr Burnham is understood to have retained Rachel Reeves’ adviser, Neil Amin-Smith, to help him with economic policy. This comes after several Labour backbenchers urged the Prime Minister to introduce a 2% tax on assets over £10 million, which they argued would raise “tens of billions” of pounds.

However, more moderate Labour figures, including those in the Labour Growth Group caucus, advocated for a “wealth tax that works.” This proposal would equalise capital gains taxes with income taxes while allowing for allowances to help incentivise investment. Mr Haldane previously stated in an interview that a wealth tax should not be used as a “cash cow.”

The deVere CEO added: “This is not a minor policy disagreement tucked away in a select committee. It’s a live fracture inside the governing party, playing out in public, a month before a Budget, with the very economists who might have helped resolve it sitting on the sidelines instead.

“Markets don’t wait for clarity before pricing risk. They price the absence of it.

“Every week Mr Burnham goes without ruling a wealth tax in or out, international investors holding UK equities, gilts, or business assets are forced to assume the worst case by default, because that is the only rational response to genuine silence from Downing Street. Keeping one adviser with Treasury experience is not a substitute for the specific credibility O’Neill, Haldane, and Hughes were meant to provide.

“Mr Burnham’s own allies built his economic reputation around their proximity before the leadership contest. This reputation cannot survive on a single holdover appointment once the people it was built on decline to show up. He has a narrow window to settle this before markets settle it for him.

“Stop leaving investors to guess. Every day this drags on without resolution makes it harder for anyone serious to treat this government’s economic credibility as more than a promise still waiting to be kept.”