Boris Johnson has been told to grow up by a Kent Conservative MP after the former Foreign Secretary compared the government's Brexit plan to a suicide vest.

Tonbridge and Malling MP Tom Tugendhat, a former soldier and chairman of the Foreign Affairs Select Committee, took Mr Johnson to task in a furious rebuke, saying the comparison was not funny.

In a tweet responding to a newspaper column by Mr Johnson, the MP recalled his own experience while serving in Afghanistan when a suicide bomber had detonated a device in the courtyard of the office in Helmand where he was stationed.

He tweeted: “A suicide bomber murdered many in the courtyard of my office in Helmand. The carnage was disgusting, limbs and flesh hanging from trees and bushes. Brave men who stopped him killing me and others died in horrific pain. Some need to grow up. Comparing the PM to that isn’t funny.”

In his newspaper column Mr Johnson said the backstop agreement signed off in December last year by the government had "opened ourselves to perpetual political blackmail".

He added: "We have wrapped a suicide vest around the British constitution - and handed the detonator to Michel Barnier [the EU's chief negotiator]."

The strength of feeling expressed by the Tonbridge and Malling MP - and his willingness to publicly criticise Mr Johnson - reflects the growing frustration amongst some backbenchers at the former foreign secretary’s outspoken interventions on Brexit since he stood down.

Mr Tugendhat saw 10 years of active service between 2003 and 2013 and served in the Intelligence Corps in both the war in Iraq and Afghanistan.

In a separate newspaper column Mr Johnson recently described the Brexit deal as a disaster for the UK.

The backstop agreement covers economic and security partnerships, possible areas of co-operation. It aims to set out a temporary customs arrangement between the UK and EU which would come into force if a permanent deal is not ready in time.