When there is a vacancy the National Executive Committee selects a provisional replacement, subject to approval at the subsequent party conference.
He also built a professional Party, with key employees working on policy development and electoral organisation.
When Len Williams, the General Secretary of the early Wilson years, retired in 1968, he was expected to be replaced by someone younger who could transform the party and lead it to a third successive victory.
Whitty oversaw the reforms of Neil Kinnock and stayed on until the election of Tony Blair as Leader.
It would be Tom Sawyer who would put in place Blair's New Labour reforms, with the creation of the National Policy Forum, the change to Clause IV and the perceived erosion of the power of grassroots members.
He opened new offices in Millbank and created a highly professional, media-savvy, youthful staff and Party that worked for Labour's landslide victory in the 1997 general election.
The roots of the transformation probably date back to the appointment of Peter Mandelson as the party's communication director in 1985, but under Blair (and Sawyer) rapidly accelerated.
He resigned after less than two years following the less than convincing 2005 general election victory and was replaced in January 2006 by Peter Watt.
[8][9] She resigned on 4 May 2020, following the election of Keir Starmer as new Labour leader, saying "now we have a new leadership team it is the right time to step down".