Is Boris Johnson running Britain in secret by WhatsApp? PM clashes with No.10 mandarin over text messages - and Carrie Symonds is said to 'prompt' him as he phones ministers

Boris Johnson has clashed with Britain’s most senior mandarin after insisting on making top secret policy decisions on WhatsApp.

Cabinet Secretary Simon Case intervened after concern that some texts from the Prime Minister’s official account on the messaging service appeared to have been sent by someone other than him.

In a separate development, Mr Johnson’s partner Carrie Symonds is understood to have been overheard ‘prompting’ him in the background during confidential phone calls to ministers and officials.

The Prime Minister has clashed with Britain’s most senior mandarin after insisting on making top secret policy decisions on WhatsApp, with some claiming to have been overheard his partner Carrie Symonds (pictured together) ‘prompting’ him in the background during confidential phone calls to ministers and officials

The extraordinary WhatsApp dispute follows a move by Mr Johnson earlier this month to extend the use of a secret Downing Street WhatsApp group for routine messages to sensitive affairs of state.

They include highly confidential policy decisions and instructions to fellow Cabinet ministers and mandarins.

In the past such matters were dealt with via traditional printed papers in the Prime Minister’s Whitehall ‘Red Box’ – which were returned by him, signed by hand.

Mr Case raised fears about Mr Johnson’s new practice, described by one official as ‘government by WhatsApp’. 

Officials said the style of some of the texted replies appeared markedly different from the Prime Minister’s own distinctive style. But he refused to go back to the old method.

Mr Johnson, Mr Case and Mr Johnson’s principal private secretary Martin Reynolds are among a handful of senior figures in the No 10 ‘Private Office WhatsApp’ group.

Until recently it was used mainly for routine messages, mainly relating to the Prime Minister’s diary.

But three weeks ago he asked to make greater use of it.

The extraordinary WhatsApp dispute follows a move by Mr Johnson earlier this month to extend the use of a secret Downing Street WhatsApp group for routine messages to sensitive affairs of state

He asked for ‘box submissions’, formal matters requiring approval, normally included in his Red Box, to be sent via WhatsApp.

However, officials became concerned by the nature of some of the texted replies.

‘The PM has a distinctive style: colourful, expressed, courteous with erratic spacing,’ said one. ‘But some replies were shorter and sharper and didn’t look or sound like him.

‘Paper documents have proved secure over decades. Unlike texts, you can see the PM’s handwritten jottings in the margins and signature.’ Mr Case is said to have raised the issue with Mr Reynolds, who said the Prime Minister would not drop the WhatsApp move.

An insider described wider concerns: ‘Previously, the Private Office WhatsApp was used for diary stuff, like reminding him he had a call to a foreign leader in 20 minutes. Now major decisions are sent in a “WhatsApp” summary. It is not the same as getting full details in a document in his Red Box. And not as secure.’

Mr Johnson is a member of several WhatsApp groups, ranging from policy forums to briefings for Conservative MPs.

It is customary for prime ministers and ministers to be given red leather briefcases, known as Red Boxes, filled with official documents, at evenings and over weekends. Officials encourage Mr Johnson to work on his Red Box while he is still at work in his No 10 study.

Officials said the style of some of the texted replies appeared markedly different from the Prime Minister’s own distinctive style. But he refused to go back to the old method. Pictured: Boris Johnson and his partner Carrie Symonds earlier this month on Remembrance Sunday

‘He is urged to do it in spare time in the office between meetings,’ said one official. ‘It means he has less to take up to the flat or Chequers.’

Claims that officials no longer put some top secret papers – ‘Strap 3’ in Whitehall jargon – in the Prime Minister’s Red Box, are disputed by No 10.

The Mail has been told that when ministers and officials are on the phone to Mr Johnson, they sometimes hear Miss Symonds in the background.

‘You can hear her prompting him, saying, “Tell him or her to do this or that,” chivvying him,’ said one. ‘It is often about her favourite issues, like the environment – or who she thinks is or isn’t loyal to him. A PM’s partner has a right to express a view.

‘But if they are listening in and contributing when the PM is talking confidentially to ministers, it would be disconcerting.’

Miss Symonds hosts regular soirees at the Downing Street flat and weekend gatherings at Chequers for her network of friends, mainly Tory political advisers and selected journalists.

Mr Johnson is present at some, but not all, of these get-togethers.

It comes after the Mail revealed how Mr Johnson blocked a plan to promote North West Durham Tory MP Richard Holden, two years after Miss Symonds gave evidence against him in a court case which cleared him of sex assault against another woman.

Mr Case, Downing Street and the Cabinet Office all declined to comment.