Cabinet minister Grant Shapps has insisted Rishi Sunak did not intervene “at all” in Boris Johnson’s honours list and claimed the party was “under new management”.

Mr Shapps, the energy secretary, dismissed suggestions the prime minister changed Mr Johnson’s honours list, telling Sky News’ Sophy Ridge On Sunday: “Occasionally Boris is not all over the detail.”

He spoke following Mr Johnson’s dramatic decision to resign as the MP for Uxbridge and South Ruislip, triggering a by-election in his constituency – a key target for Labour.

Mr Johnson announced he was standing down as an MP with immediate effect on Friday after receiving the report into whether he lied to MPs over partygate.

In an excoriating statement, the former prime minister said a letter from the privileges committee made clear “that they are determined to use the proceedings against me to drive me out of parliament”.

Mr Johnson was joined by former culture secretary Nadine Dorries and former minister Nigel Adams, who are also both standing down in their constituencies of Mid Bedfordshire and Selby an Ainsty.