The Lost Homestead, said two years on from her diagnosis she could see she “was lucky”.
She and the prime minister met while attending the European School in Brussels as children, and married after the annulment of Mr Johnson’s marriage to his first wife, Allegra Mostyn-Owen.
Marina Wheeler at the opening ceremony of the 2012 Olympics in London
(PA)
Mr Johnson’s personal life has long been under public scrutiny.
The Appeal Court ruled in 2013 that the public had a right to know that he had fathered a daughter during an affair while he was the mayor of London.
Previously, he was sacked as shadow arts minister in 2004 after it was reported he had had an affair with journalist Petronella Wyatt – a year after he married Ms Wheeler.