Responding to the announcement, the Labour Party in London said: “London represents everything Reform UK opposes: multiculturalism, openness and confidence in our shared future.”
It said the announcement of Cunningham “confirms that Reform UK are offering the capital nothing but division and decline”.
The spokesperson added: “Cunningham has made a habit of talking London down, repeatedly portraying our city as broken while opposing the multiculturalism that makes it the best city in the world.”
A source close to London’s mayor said Sir Sadiq was “getting on with the job of delivering a fairer, safer, greener city for every Londoner”.
Liberal Democrat London spokesperson, Luke Taylor MP, said: “From its history, to its culture, to its people, London is the greatest city in the world, but all Reform seems to do is talk it down.
“Cunningham and Farage care more about sowing division than they do about solving the actual problems that Londoners face.
“The Liberal Democrats will stand up for the millions of Londoners who love this city and its values and ensure London is a better place for everyone.”