Boris Johnson has surged back into the lead as the Tory grassroots favourite to become the next party leader, after quitting as foreign secretary over the government’s Brexit plan.

According to the latest survey conducted by Conservative Home, Johnson now has the support of almost a third of party members.

One month ago, while still serving in the government, Johnson was far behind in fifth place, with the support of just 8%. He was last in the lead in March 2016.

But in this month’s poll he has the backing of 29% of party faithful, far ahead of second-placed Home Secretary Sajid Javid on 19%.

Jacob Rees-Mogg, who emerged as the leading backbench Tory Brexiteer while Johnson was in the Cabinet, is in third place with 13% of the vote.

Michael Gove, who was second in last month’s survey on 17%, is now in fifth place on 7%.

Johnson quit as Foreign Secretary in early July in protest at Theresa May’s Brexit plan.

In his resignation speech in the Commons, Johnson attacked the Prime Minister’s “miserable” Chequers proposal as a “democratic disaster” that gave in too much to what the EU wanted.

He said “a fog of self-doubt has descended” over the UK government’s approach to negotiations as it “dithered”.