The wife of Dominic Cummings has denied that she is the second woman whom Boris Johnson is accused of having groped at a lunch 20 years ago.

Mary Wakefield, who is married to the prime minister’s chief adviser, said yesterday that she was not involved in the incident, which allegedly took place during a private lunch at The Spectator shortly after Mr Johnson became its editor in 1999.

Her statement was made in response to rumours. The prime minister has denied the allegation.

Charlotte Edwardes made the accusation in a column for The Sunday Times. She wrote in her account of the event: “I’m seated on Johnson’s right; on his left is a young woman I know. More wine is poured; more wine is