Labour Party Shadow Chancellor John McDonnell | Daniel Leal-Olivas/AFP via Getty Images UK Labour: Delist companies that fail to tackle climate change John McDonnell said companies could publish decarbonization plans and improve climate-related financial reporting.

LONDON — A Labour government would delist companies that fail to take steps to tackle the climate crisis, Shadow Chancellor John McDonnell announced today.

Companies must contribute to greening the economy or else get “delisted from the London Stock Exchange,” McDonnell said in a speech in Westminster.

“The Corporate Governance Code and legislation will be amended to set out a minimum standard for listing related to evidencing the action being taken to tackle climate change,” the shadow chancellor said. The policy will appear in the Labour party's election manifesto which will be unveiled Thursday.

McDonnell cited publishing decarbonization plans and improved climate-related financial reporting as examples of steps that companies could take.

“Tackling the existential threat of climate change is Labour’s overriding priority as we enter government,” he said. “If we are to meet the climate change target to keep global warming to 1.5 degrees above pre-industrial levels, we need to ensure that companies are pulling their weight alongside government.”

"Tackling the existential threat of climate change is Labour’s overriding priority as we enter government." — John McDonnell

McDonnell first said he was considering the measure in an interview with the Guardian in May. He said then that the proposals were about “weeding out those that are not taking it seriously.”

He confirmed the policy in a speech to City leaders hosted by UK Finance in June. “When we de-list companies that fail to meet environmental criteria from the London Stock Exchange, investors can be confident that their money is not going on making the world uninhabitable for their children,” he said then.

As a backbench MP, McDonnell had proposed that the criteria for a listing a company on the London Stock Exchange should include human rights, trade union rights and environmental policy.