Labour may have to cancel its annual conference unless it signs a deal with a new security company after taking the decision to boycott G4S.

The party has failed to get a new company on board after cancelling its deal with G4S because of its links with Israeli prisons, according to leaked emails to Iain McNicol, Labour's general secretary.

There are concerns the Home Office and police could shut down the conference, set to start on Sept 25, if Labour fails to source its own security.