Grassroots Tories have demanded changes to the Conservative Party’s leadership election rules to ensure Boris Johnson is on the final ballot paper.

The former foreign secretary is the runaway favourite among Party members to replace Theresa May, but they fear a “stitch-up” by rivals who want to keep him out of Downing Street.

Under the current rules, MPs whittle down the candidates in a series of ballots until only two are left, who then go head to head in a membership vote.

But after the “disastrous” leadership election in 2016, when Theresa May was crowned as the winner before members had any say, activists want the rules changed so that their preferred candidate must be taken into account.

Mr Johnson announced his intention to stand on Thursday - the day that Theresa May agreed to quit within weeks - and had already been quietly building up support from MPs through dozens of one-to-one meetings in his parliamentary office.