The deputy leadership contest is seen as a critical moment for the Labour government, facing a significant challenge from the rise of Reform UK.
Both Dame Emily Thornberry and Andy Burnham have urged Sir Keir Starmer to listen more to backbenchers and party members.
Andy Burnham, mayor of Greater Manchester, expressed concerns about the balance of Sir Keir's cabinet and called for a less factional, more pluralistic party management style.
The contest is being viewed by some as a referendum on Sir Keir Starmer's leadership.