Labour's boycott of security giant G4S could jeopardise the party's annual conference in Liverpool next month. The party has apparently failed to find a new firm after its governing body, the National Executive Committee, voted to drop G4S in 2015, reputedly over its ties to Israel's prison system.

A leaked email from Simon Mills, Labour's deputy treasurer, to general secretary Iain McNicol warned that the Home Office or Merseyside Police could stop the conference if the party is unable to find another contractor, the Guido Fawkes blog first reported on 4 August.

Labour could also end up upsetting one of the party's trade union affiliates and donors if they hire Showsec.

That is because GMB is in dispute with the Leicester-headquartered employer. The news comes as Jeremy Corbyn and Owen Smith continue to battle it out for the Labour leadership.

Kate Green, the chief of Smith's campaign, today called on McNicol to extend the contest by two weeks after the High Court ruled against Labour's NEC decision to stop members who joined after 12 January voting in the election.

Labour has contested the decision in the Court of Appeal today and a ruling is expected tomorrow. Merseyside Police had not responded to a request for comment at the time of publication, while a Labour spokesperson said: "We don't comment on leaked documents."