Former prime minister Boris Johnson has breached UK Government rules by being “evasive” about his relationship with a company that set up a meeting between him and Venezuela’s President Nicolas Maduro, the business appointments watchdog has said.

Lord Pickles, chairman of the Advisory Committee on Business Appointments (Acoba), has written to both Mr Johnson and Deputy Prime Minister Oliver Dowden warning of the breach.

It comes after the former Conservative prime minister failed to clarify his relationship with a company called Merlyn Advisors, a hedge fund.

Mr Johnson is reported to have met Mr Maduro alongside Merlyn Advisors co-founder Maarten Petermann in February.

Lord Pickles wrote in his letter to Mr Dowden: “Mr Johnson has repeatedly been asked by Acoba to clarify his relationship with Merlyn Advisors.

General Election 2017 aftermath
Lord Pickles is chairman of the Advisory Committee on Business Appointments (Victoria Jones/PA)

“He has not done so, nor has he denied the reports in the media that he has been working with Merlyn Advisors on a non-contractual basis.”

Government rules state former ministers must not take up new jobs or appointments for two years after leaving public office without advice from Acoba first.

In correspondence dating back to March 18, the watchdog contacted Mr Johnson’s office asking him to set out his relationship with Merlyn Advisors following media reports of his South American visit.

He replied he had no contractual relationship with the company, and in further correspondence said he had not been paid for any meetings in Venezuela.

He added: “I was extensively briefed by HMA (His Majesty’s Ambassador) Caracas before the meeting and used the occasion to push for democracy, human rights and the support of Ukraine.”

Lord Pickles raised concerns that the trip was paid for by Merlyn Advisers and about the nature of Mr Johnson’s activities for the company, even though he was not under any formal contract.

The peer warned: “If that is the case, there is a reasonable concern that you were acting in a capacity that would be inconsistent with Acoba’s guidance on ‘one-off’ speaking engagements – which does not provide blanket approval for ad-hoc advisory work.”

Oliver Dowden Chatham House speech
Lord Pickles has written to Deputy Prime Minister Oliver Dowden on the issue (Yui Mok/PA)

Mr Johnson did not answer further questions from Lord Pickles about the nature of the meetings or his relationship with Merlyn, and said he believed it was “clearly not necessary to consult or seek Acoba” about the work.

But the watchdog chief disagreed and said there “remains a reasonable concern that you were acting for Merlyn Advisors in a capacity that would be considered advisory work”, which Acoba would have expected him to ask advice for.

He added: “Given the evasive nature of your replies, your failure to answer specific questions put to you, or provide the context of your relationship with Merlyn Advisors, the committee has formed the view that there has been a breach of the Government’s business appointment rules.”

Lord Pickles then reported the former prime minister’s actions to Mr Dowden, who is also responsible for overseeing the Cabinet Office, the department which oversees the machinery of Government.

He admitted there was little action which could be taken against Mr Johnson, as the rules “no longer have relevance in the modern world and are unenforceable to applicants determined to ignore them”.

The Government should reform the rules as it promised in July 2023, Lord Pickles said, to ensure those who breach them faces consequences.

The reforms, which could strengthen enforcement against breaches of the rules, are still being worked on within Government, it is understood.

Labour said Acoba’s admonishment of Mr Johnson showed “this rotten Conservative Party simply cannot change”.

Nick Thomas-Symonds, a shadow Cabinet Office minister, said: “Boris Johnson has once again demonstrated a complete disdain for the rules, while Rishi Sunak is too weak to do anything about it. This now creates serious and urgent questions for the Government to answer.

“The rules in place to stop this revolving door are wholly inadequate – and completely toothless, they expose repeated broken Government promises to reform the system.

“Only Labour has a plan deliver the change we need. Our ethics and integrity commission will stop the revolving door; we will make the rules enforceable, with proper monitoring and clear sanctions for those who break them.”

A spokesman for Mr Johnson did not wish to comment.