The Conservatives have demanded Labour investigate “alarming revelations” that a think tank linked to the Party made “baseless claims” about journalists who were investigating it.

The calls add to pressure on the Cabinet Office minister Josh Simons, who commissioned a 2023 report on journalists investigating Labour Together.

The thinktank helped propel Sir Keir to power in 2024.

Kevin Hollinrake MP, chairman of the Conservative Party, said: “Labour Together’s behaviour shows a worrying contempt for the free press, a fundamental foundation of our democracy.

“With its close and widely known links to the heart of Government, serious questions must be answered about who was aware of these actions, including whether senior figures around the Prime Minister knew.

“After Starmer’s attempts to deflect from the Mandelson-Epstein affair, the public will accept nothing less than full transparency.

The Sunday Times reported claims that Labour Together hired lobbyists from US firm APCO to investigate the personal, political and religious background of journalists, in order to build material for a smear campaign against them.

Among them was Gabriel Pogrund, who had been investigating Labour Together’s £720,000 of undeclared donations.

In an agreement addressed to Mr Simons, drawn up by Apco Worldwide, the PR consultancy said it would “investigate the sourcing, funding and origins” of a November 2023 Sunday Times report about the think tank, in addition to other journalistic investigations into the group.

The Sunday Times reported that the contents of Apco’s investigation were informally shared with Labour figures in 2024, including present cabinet ministers and special advisers

Mr Simons, who reportedly engaged APCO, is now the Cabinet Office Minister in charge of inquiry policy.

Several other figures linked to Labour Together are in senior Cabinet roles.

A Downing Street source said there was no reason for Sir Keir to have known about the document and he was not in charge of Labour Together.

Mr Simons told The Sunday Times: “I was surprised and shocked to read the report extended beyond the contract by including unnecessary information on Gabriel Pogrund.

“I asked for this information to be removed before passing the report to GCHQ. No other British journalists were investigated in any document I or Labour Together ever received.”

Alison Phillips, the CEO of Labour Together, has written to all staff at the organisation on Sunday night.

She says she is "horrified" by the "shocking" allegations but added she has been assured it was not the "intention" to look into the background of reporters.

Alison Phillips, the CEO of Labour Together, has written to all staff at the organisation on Sunday night.

She says she is "horrified" by the "shocking" allegations - but adds she has been assured it was not the "intention" to look into the background of reporters.