Sadiq Khan has been reselected as Labour’s London mayoral candidate ahead of the May 2020 election. Though the party has yet to make an official announcement, the mayor has now passed the 50 per cent threshold in the “trigger ballot” process, sources close to Labour’s London Regional Board have told the New Statesman.

Since June, Constituency Labour Parties (CLPs) in London, and all organisations and trade unions affiliated to the London Labour Party, have been voting on whether to automatically reselect Khan or instead to hold an open selection (allowing other candidates to stand).

To date, Khan has won the support of more than 25 CLPs, including many of the largest and most polarised such as Walthamstow, Dulwich and West Norwood and Hornsey and Wood Green. However, Hampstead and Kilburn, a seat held by Khan-ally Tulip Siddiq, voted by 32-28 to hold an open selection, and in Bromleyand Chislehurst the vote was tied (which Labour treats as support for an open selection). Both votes are said to reflect support for the principle of mandatory reselection, rather than hostility to Khan.

The mayor has also won the support of the GMB, Unison, ASLEF, CWU, TSSA, USDAW, and Community trade unions (Unite has yet to vote). In advance of Labour’s conference this month, the remaining CLPs and affiliates will continue to vote but it is now arithmetically impossible for an open selection to be triggered.

Khan was elected London mayor against the Conservatives’ Zac Goldsmith in 2016 with 57 per cent of the vote (1.3 million votes), the largest personal mandate of any politician in UK history. The support for Khan from Labour activists will be seen as a sign of strength at a time when members are increasingly asserting their democratic rights.

In the last week, no confidence motions have been passed against three MPs: Chris Leslie, Joan Ryan and Gavin Shuker. A Momentum petition backing open parliamentary selections has received 10,000 signatures in less than four days.

Khan endorsed Owen Smith in the 2016 Labour leadership election and has regularly criticised Labour’s handling of anti-Semitism (Khan was unanimously approved by Finchley and Golders Green CLP, a constituency with a large Jewish community). The mayor has also supported a potential second Brexit referendum if parliament votes against any deal, a stance overwhelmingly backed by party members.

In recent weeks, Khan has faced fierce criticism from the London Evening Standard, leading to claims that the paper, edited by former Conservative chancellor George Osborne, has been coordinating lines with the Tory party (a suggestion described by a Standard spokesperson as “laughable and entirely false”).

The ballot for the Conservative London mayoral selection opens on Monday, with London Assembly members Shaun Bailey and Andrew Boff, and Ealing councillor Joy Morrissey the three shortlisted candidates. The party will hope for greater turnout than in 2015 when just 9,227 members participated, with 6,514 (71 per cent) voting to back Zac Goldsmith.