Jeremy Corbyn’s team is increasingly convinced there will be a 2017 general election and have made preparing the party for a snap vote their “number one priority”.

A recruitment drive is underway to hire staff “across the country” while they are reviewing the rules for electing candidates in seats they do not hold.

Senior Labour figures have told The Sunday Telegraph they have millions of pounds gained from a membership surge to spend in their “remorseless” preparation.

There is also a new push to turn hundreds of thousands of new members into active campaigners who can knock on doors to rally support.