The Cabinet Office has said it will examine the facts surrounding accusations that Labour Together engaged a public affairs firm to probe the background of a journalist. Technology Secretary Liz Kendall said ministers would look into what happened and stressed the importance of press freedom.

The report, known as “Operation Cannon”, was commissioned while Josh Simons was head of Labour Together. Simons is now a Cabinet Office minister. Labour Together paid APCO Worldwide at least £30,000 to look into the “sourcing, funding and origins” of a Sunday Times story about undeclared donations at a think tank before the 2024 general election, according to reporting and documents seen by news organisations.

Sources familiar with the material have told reporters that the APCO document included information about Sunday Times journalist Gabriel Pogrund’s Jewish beliefs and assertions about his political stance. The report is also said to have suggested that some of Pogrund’s previous reporting “could be seen as destabilising to the UK and also in the interests of Russia’s strategic foreign policy objectives”.

Those sources said the report was prepared by a former Sunday Times employee who is now employed by APCO Worldwide.

An APCO Worldwide spokesperson said: “We are deeply committed to upholding our values and standards as an organisation and treat any suggestion that we have failed to do so very seriously. “

“We are in the process of undertaking a detailed internal review of the project. “

“We are also in discussion with the PRCA [Public Relations and Communications Association], of which we are longstanding members, and will fully support them in their own review of this matter.”

Josh Simons said APCO had exceeded the scope of its instructions. He said he was “surprised and shocked to read the report extended beyond the contract by including unnecessary information on [Sunday Times journalist] Gabriel Pogrund”.

Simons added that he had asked for “this information to be removed” before passing the report to the intelligence, security and cyber agency GCHQ. He previously described claims he wanted to investigate journalists as “nonsense” and said he had asked APCO Worldwide to “look into a suspected illegal hack, which had nothing to do with UK journalists at Sunday Times, Guardian or any other brilliant UK newspaper”.

Ben Taylor, editor of the Sunday Times, said the “excuses” of those at the top of Labour Together “won’t wash”. He told BBC Radio 4’s Today programme: “When the report came in, Labour Together people, some of whom are now in the cabinet, were quite happy to talk about its conclusions widely around Westminster – claims that the Sunday Times was being used by the Russian state to run disobliging stories about Labour and frankly cast doubt on the title and their reporters.”

Tory chairman Kevin Hollinrake criticised the actions, saying Labour Together’s behaviour “shows a worrying contempt for the free press”. He added: “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.”

Former Labour shadow chancellor John McDonnell, who says he raised the issue after being contacted by Democracy for Sale, said he believed these were “serious allegations” and that the “Labour Party should get on top of it”. He also said his reply from the party’s general secretary indicated Labour Together was not a Labour organisation and that he was referred to the complaints department about individual members of the party. “I said that doesn’t meet the seriousness of this case,” he added.

Alison Phillips, chief executive of Labour Together who joined after the APCO report was commissioned and delivered, said: “I am committed to ensuring Labour Together aspires to the highest standards of probity at all times.” She also said: “We stand ready to support the PRCA [and other relevant governance bodies] with its review of this issue.”

Liz Kendall told the Today programme: “The Cabinet Office will look at the facts around what has happened here.” She went on: “The freedom of the press is absolutely essential for me personally, and the government as a whole.” She also said: “The journalists that were looked into here, they are journalists of great experience and great integrity.”

Asked about Mr Simons’ ministerial position, she said: “He has welcomed the investigation, rightly so, by the regulatory body.”

• APCO Worldwide has begun an internal review and is liaising with the PRCA.
• Labour Together has indicated it will cooperate with regulatory reviews.
• The Cabinet Office has said it will examine the facts surrounding the commissioning and handling of the report.