The Tories will give every Clacton constituent - not just their members - a chance to choose their candidate at an open primary selection meeting next week.

The Conservatives confirmed today that they will be holding a ballot of all voters to decide who they will pit against defector Douglas Carswell.

The Tories will be writing to everyone on the electoral roll in the area today, inviting them to the meeting on September 11, ahead of a by-election on October 9.

The first British open primary was held in 2009 when Sarah Wollaston, a GP with no experience of politics, was chosen as a Tory candidate, and subsequently won.

She is now the chairman of the influential health select committee in the Commons.

The announcement comes after Roger Lord, UKIP’s candidate for the Clacton Parliamentary seat before Conservative MP Douglas Carswell’s shock defection to the anti-European Union party last week, sensationally resigned his Brightlingsea seat at County Hall and quit the UK Independence Party yesterday.

The move has caused waves at Essex County Council too, with Conservative leader David Finch saying UKIP in Essex is in “chaos”.