Southampton City Council does not believe there is “any valid cause of action” by another council which has threatened to sue the Hampshire local authority.

Thurrock Council is in the midst of a dispute with the Association for Public Service Excellence (APSE) – the organisation which valued the solar farms that were part of its crippling investment strategy.

The Essex authority declared effective bankruptcy two years ago after losing £200million from the deals between 2017 and 2020.

Last week, Thurrock issued a statement accusing APSE of “negligent” overvaluation of the assets and urging it to agree “a way forward” after months of negotiations.

The deadline for legal claims against the association, which is owned by its membership of more than 250 UK local authorities, is reportedly Tuesday, November 19.

In response, APSE said it was “extremely disappointed” Thurrock had released a statement which “risks undermining sensitive discussions” with its member councils.

APSE denies the allegations made by the borough council.

Thurrock has now threatened to sue 23 other local authorities, including Southampton City Council, which are part of APSE in an attempt to claw back some of the millions of pounds it lost, according to a report by The Bureau of Investigative Journalism.

In a statement to the Local Democracy Reporting Service, Richard Ivory, Southampton City Council’s director of legal and governance, said: “We do not believe there is any valid cause of action by Thurrock Borough Council against this authority and if any proceedings are issued they will be vigorously defended.

“We cannot comment any further at this point in time.”

Thurrock’s statement said while its primary focus was on recovering money from Liam Kavanagh and companies within the Rockfire group, which owned the solar farms, it had a “duty” to pursue those whose actions led to the “poor” investments.

Cllr John Kent, leader of Thurrock Council, said: “While our primary focus is on recovering money from those who sought to line their own pockets from the public purse, we have a duty to consider all lines of recovery.

“This includes pursuing those organisations whose incorrect advice also contributed to the council’s decision to make the poor investments.”