Former top civil servant warns ‘more due diligence’ to be done over replacement of Chris Wormald

Sir Simon McDonald, above, was permanent secretary of the Foreign Office when Antonia Romeo was consul general in New York. While in that job, Romeo faced questions about her spending Photograph: Will Oliver/EPA

A former top civil servant has urged No 10 to do “more due diligence” as it prepares to replace the cabinet secretary, Chris Wormald, with Antonia Romeo, the frontrunner for the role.

Sir Simon McDonald, the former permanent secretary of the Foreign Office, said he had tried to warn No 10 the process needed to start from scratch and it was vital that the prime minister followed a thorough procedure given the importance of the role.