But during his campaign, he said the speakers had his “full support” and told campaigners: “It’s really important that you get the politicians to come out and support you and be with you on this.
“I am very proud to be doing that, to be with you this morning and to support you during this campaign, both as an MP here, from the shadow cabinet, and as the leader of the Labor Party.
“My leadership, if I win it, will be with you and other campaigns like you so we can win [on] issues like this that are so important.”
‘Proud trade unionist’
Sir Keir described himself as a “proud unionist” in a campaign video and had joined UCU workers in a separate picket in December 2019 in the week before the general election.
But this summer he stopped short of endorsing recent industrial action on the railway, despite saying he supported workers’ “right to strike”.
Campaign group Momentum, which was set up to back Jeremy Corbyn’s hard-left policies, said his comments represented “leadership that was promised to us and then denied”.
The group said in a statement: “We will not let Keir Starmer drive a wedge between Labor and the trade union movement. Defending the interests of workers is the founding mission of the Labor Party.
“In the coming weeks we will be campaigning across the country for every Labor MP to stand with Labour.”
Diane Abbott, MP for Hackney North and Stoke Newington and one of Corbyn’s closest political allies, tweeted the images saying: