The Labour Party has reported Boris Johnson to the Parliamentary Commissioner for Standards.
It comes after allegations BBC chairman Richard Sharp helped the former prime minister to arrange a guarantee on a loan of up to £800,000 just weeks before he was selected for his current job.
Anneliese Dodds, the Labour chair, has written again to Daniel Greenberg CB raising concerns about the alleged arrangement and suggested it could have constituted a breach of the Code of Conduct for MPs.
Ms Dodds said: “The financial affairs of this disgraced former prime minister just keep getting murkier, dragging the Conservative Party deeper into yet another quagmire of sleaze.
“Serious questions need to be asked of Johnson: why has this money never been declared, and what exactly did he promise these very generous friends in return for such lavish loans?”
The Sunday Times reported Mr Sharp was involved in talks about financing Mr Johnson‘s Downing Street lifestyle in November and December 2020.
Sam Blyth, a multimillionaire Canadian businessman and distant cousin of the former prime minister, is said to have raised the idea of acting as Mr Johnson’s guarantor, and reportedly asked Mr Sharp for advice on the best way forward.
The now BBC chairman agreed to help and introduced Mr Blyth to Simon Case, the cabinet secretary and head of the civil service shortly afterwards, the paper reported.
In Ms Dodds’ letter to Mr Greenberg, the Labour MP said the “lack of transparency” on the issue could “call into question the process by which the chairman of the BBC was appointed” – as this selection was in its final stages at the time.
The SNP has also called for an independent inquiry.
Kirsty Blackman, the SNP’s Cabinet Office spokesperson, said the existence of the facility, and the appointment of Mr Sharp to the £160,000 a year role as BBC chairman by Mr Johnson, “reeks of Tory sleaze”.
“The UK government must establish an independent inquiry to assess the circumstances of this loan, the propriety of the arrangement, the ethics of the appointment, and whether any rules were broken by Mr Johnson, the UK government or the BBC chairman,” she said.
“Many people will have serious concerns about the existence of this loan, the circumstances of arranging it, and the increasingly close relationship between the Tory government and senior management at the BBC. This murky arrangement stinks to high heaven.”
Responding to the report, Mr Sharp told The Sunday Times: “There is not a conflict when I simply connected, at his request, Mr Blyth with the cabinet secretary and had no further involvement whatsoever.”
A BBC spokesman said: “The BBC plays no role in the recruitment of the chair and any questions are a matter for the government.”
A spokesman for Mr Johnson told the paper: “This is rubbish. Richard Sharp has never given any financial advice to Boris Johnson, nor has Mr Johnson sought any financial advice from him. There has never been any remuneration or compensation to Mr Sharp from Boris Johnson for this or any other service.
“Mr Johnson did indeed have dinner with Mr Sharp, whom he has known for almost 20 years, and with his cousin. So what? Big deal. All Mr Johnson’s financial arrangements have been properly declared and registered on the advice of officials.”