Wealth management group St James's Place plc has dealt under-pressure city heavyweight Neil Woodford another major blow after ending its £3.5 billion association with his firm.

The firm – which has several partner practices based across Cumbria – has terminated its mandate with Woodford Investment Management, which reportedly represented 40 per cent of the £8.6 billion under his oversight.

Mr Woodford was responsible for the firm's UK High Income Unit Trust, UK Equity (Life and Pension), Income Distribution (Life) and SJPI UK High Income funds.

One of Britain's leading stock pickers, Mr Woodford was recently forced to apologies to investors and reassure them that plans were in place to stabilise his flagship multi-billion-pound fund, after it was suspended amid a surge in redemption requests.

The Woodford Equity Income Fund – the company's largest, with a reported value of £3.7 billion – was frozen shortly after Kent County Council to withdraw its £263 million invested in the fund.

Mr Woodfood is under pressure from investors, who want access to their cash, and now the Financial Conduct Authority (FCA), which is demanding answers from Mr Woodford and his brokers over their decision to invest so heavily in unlisted companies based offshore in Guernsey.

While the FCA has stressed that there is no suggestion of wrongdoing at Woodford Investment Management, it wants to understand the chain of events leading to the suspension.

In a statement to the London Stock Exchange, St James's Place plc explained the rationale behind its decision to cut ties. 

It said: “While the St. James's Place funds managed by WIM were separate mandates and not part of the Equity Income Fund suspended earlier this week, the St. James's Place Investment Committee believes these changes will ensure its clients' investments continue to be managed effectively.”

The former Woodford Investment Management mandate will now be picked up by Columbia Threadneedle Asset Management and RWC Partners.

Mr Woodford as been a regular in the media spotlight in recent months.

He found himself at the centre of a bitter boardroom battle at Stobart Group, which pitted Cumbrian tycoon Andrew Tinkler against the Carlisle-headquartered group’s board.

Funds acting through Woodford Investment Management, along with other major Stobart Group shareholder Allan Jenkinson were part of the push by Mr Tinkler to oust the group’s chairman Iain Ferguson and replace him with Edinburgh Woollen Mill boss and Cumbria’s richest man, Philip Day.

Mr Woodford eventually ended up giving written evidence in the high-profile High Court hearing into whether Stobart Group bosses had lawfully sacked Mr Tinkler from the board.

He branded accusations that he had been party to a 'conspiracy' to use 'unlawful means' to 'injure the company' levelled against him by Stobart Group, as “completely unfounded”.

Mr Woodford – who has managed funds invested in Stobart for more than a decade – said his backing of Mr Tinkler was in the best interests of the funds he managed and Stobart Group.

The High Court eventually ruled in Stobart Group’s favour and has made a series of board appointments in a bid to “reunite stakeholders”, including new chair David Shearer, who took up the post at the beginning of the month.