Former foreign secretary Boris Johnson and his wife Marina Wheeler have announced that they have separated and are going through the process of divorce.

In a joint personal statement issued to the Press Association through a family friend, the couple said that their separation occurred “several months ago”.

The announcement comes after The Sun revealed on its front page that the Conservative MP and his lawyer wife, both 54, were no longer living together.

BrexitBoris Johnson and his wife Marina Wheeler leaving Carlton House Terrace in Westminster, London, after he resigned as Foreign Secretary (Isabel Infantes/PA)

In their statement, Mr Johnson and Ms Wheeler said: “Several months ago, after 25 years of marriage, we decided it was in our best interests to separate.

“We have subsequently agreed to divorce and that process is under way.

“As friends we will continue to support our four children in the years ahead. We will not be commenting further.”

Mr Johnson was a childhood friend of Ms Wheeler – the daughter of BBC journalist Charles Wheeler – when they were both pupils at the European School in Brussels.

He met his first wife Allegra Mostyn-Owen while they were students at Oxford, and they wed in 1987, but the marriage was annulled in 1993 and he married Ms Wheeler later that year. The couple have two sons and two daughters.

Mr Johnson has repeatedly come under scrutiny over his personal life. The Appeal Court ruled in 2013 that the public had a right to know that he had fathered a daughter during an adulterous liaison while Mayor of London in 2009.

Boris Johnson divorceBoris Johnson and his wife Marina Wheeler campaigning together during the 2008 mayoral election race (Stefan Rousseau/PA)

In 2004 he was sacked from the Tory frontbench over a reported affair with journalist Petronella Wyatt.

It is not known whether the couple’s decision to separate pre-dates Mr Johnson’s resignation as Foreign Secretary. The pair were photographed together moving out of his official residence Carlton House Terrace shortly after he quit the Cabinet.

News of the divorce comes as Mr Johnson is at the centre of intense speculation over a possible challenge to Theresa May as leader of the Conservative Party and Prime Minister.

He walked out of Mrs May’s Cabinet in July in protest at her Chequers plan for future relations with the EU, and this week used his regular column in the Daily Telegraph to condemn her Brexit blueprint as a disaster.

He is due to address fellow eurosceptics on the fringe of this month’s Conservative Party conference in Birmingham, in an intervention which threatens to overshadow Mrs May’s efforts to rally activists behind her plan.

In Westminster, speculation was rife over whether Mr Johnson may have made news of his impending divorce public in order to “clear the decks” ahead of a leadership bid.

One unnamed ally was quoted by the Daily Mail as saying: “I believe it is in Boris’s interests to get this news out there now so it is not used by his enemies in the height of a leadership contest.

“This means that if and when he goes for the top job, it will be old news and cannot harm him.”