Sadiq Khan has been reselected as Labour's candidate for London Mayor after he reached the 50% plus 1 threshold in the trigger process that has been running throughout August and September. 

The process is that Sadiq had to get 50% of the combined 2 sections of the ballot the CLP section and the Affiliate section. CLPs and Affiliates held internal ballots of whether or not to support Sadiq. 

He was taken over the threshold by the support of the GMB Union, that issued a press release early this morning proclaiming their support for Sadiq.

Sadiq himself said on Twitter

To every @LondonLabour & trade union member that has put their trust in me to be Labour's candidate for London Mayor in 2020: thank you.

Winning again won’t be easy but together, we can continue working hard every day to improve the lives of Londoners. https://t.co/6zxbnW7cmG

— Sadiq Khan (@SadiqKhan) September 14, 2018