Boris Johnson mocks Conservative Party chairman over MP data breach in Tory fringe speech

'I know this conference is going to be a staggering success because just in the last few days about a dozen hard-left Momentum activists have taken the trouble to ring my personal mobile phone,' Mr Johnson said

Boris Johnson has used a speech on the fringes of the Conservatives' annual conference to mock the party chairman over a data breach that led to the leak of ministers and senior politicians' contact details.

The former foreign secretary was among a number of high-profile Conservatives to be contacted by members of the public on his personal mobile number after the security breach was discovered at the weekend.

Users of the party's conference app noticed they could access private data for any attendees, simply by logging in using an email address and without being prompted for a password.

Addressing the debacle, Mr Johnson told delegates on Tuesday: "I know this conference is going to be a staggering success because just in the last few days about a dozen hard-left Momentum activists have taken the trouble to ring my personal mobile phone and pledge and support.

"Of course, I passed them straight onto Brandon [Lewis]".

The left-wing columnist, Owen Jones, was among those to have sent Mr Johnson a message on his personal number shortly after the leak, requesting an interview with him for the Guardian.

Following the major breach on Sunday, Mr Lewis said the party was treating the system flaw as a "serious matter" which affected a "limited number" of people.

As Mr Johnson addressed the party faithful, James Duddridge, Conservative MP for Rochford and Southend East and a subscriber to the staunchly pro-Brexit European Research Group, gave Mr Johnson his support.

"Turns out there is a plan. That plan is Boris. £brexit," he tweeted.

Before Mr Johnson appeared on stage, however, the business minister, Claire Perry, dismissed the significance of her colleague's one-day visit to Birmingham. "It's a travelling circus that comes to town," she told Sky News.

"He thrives on publicity, he doesn't have a policy backbone anywhere on him. Who doesn't want to see the court jester arrive? But behind the scenes all the deadly serious work of delivering Brexit goes on."