A vote on Theresa May's future among the party's grassroots supporters which could hasten her departure from office is just weeks away after enough local party chairmen signed a petition supporting it.

The National Conservative Convention, which represents Tory volunteers, now has a duty under the party's constitution to call an "extraordinary general meeting" to allow a no confidence vote in Mrs May to be held.

Any vote would be unprecedented and would put pressure on Conservative MPs to change the leadership rules and allow them to hold an early vote on Mrs May's future which could see her being forcibly removed from office.

Campaigners said the scale of support was “a clear expression of just how disillusioned, despairing and disappointed the Conservative grassroots have become”.

They said that any vote “will add weight to moves by the 1922 Committee to change their procedure, to allow for a further confidence vote in the Prime Minister by MPs”.

MPs on the executive of the 1922 committee of backbench Tory MPs are meeting on Tuesday to discuss an early vote, rather than waiting until December as they have to under current rules.

The ‘no confidence’ vote has been triggered after 70 association chairmen – five more than required under party’s constitution – signed a petition asking Mrs May to “consider her position” as party leader.