The secret ballot carries no formal weight but significant support for the motion would undoubtedly damage Mr Corbyn’s leadership and show potential challengers if they were likely to have the requisite support from their colleagues to trigger a contest. Any Labour MP wanting to challenge Mr Corbyn would require the support of at least 20 per cent of their parliamentary colleagues – that equates to about 50 signatures. A formal contest would then take place at the Labour Party’s autumn conference at the end of September. It is currently unclear whether Mr Corbyn would automatically be on the ballot but there is speculation that the Party’s National Executive Committee could make that happen. Once a line up is finalised, the election would take place on a one-member-one-vote basis with members, affiliates and registered supporters taking part.