The shadow chancellor, John McDonnell, will give evidence in the trial of 13 climate change activists who are alleged to have occupied a Heathrow runway in July in protest at the airport’s expansion.



The Labour MP, whose Hayes and Harlington constituency includes the UK’s largest airport, has been a prominent opponent of the airport’s third runway and has strongly backed local residents who are resisting the move.

He is expected to argue that the demonstration was justified because the aviation lobby had threatened to wield too great an influence over the decision and that local people have been ignored in consultations on the airport’s future.

At a rally in October, McDonnell said: “In my constituency, at the moment, people are literally dying. They’re dying because the air has already been poisoned by the aviation industry. They’ve promised us after every inquiry: no further expansion. They are liars. They have consistently lied to us. They now tell us if they get a third runway, there’ll be no increase in noise and no increase in pollution. They’re liars.”

The trial, which starts on Monday at Willesden magistrates court in London and is expected to last two weeks, will also hear evidence from the Green party leader, Natalie Bennett, the Greens’ London mayoral candidate, Sian Berry, the Guardian columnist George Monbiot and prominent US climate scientist Steve Barrett.



The 13 activists, who range in age from 23 to 67 and demonstrated under the banner of the Plane Stupid group, have all pleaded not guilty to aggravated trespassing and entering a security-restricted area of an aerodrome. They face up to three months in prison.

They are expected to argue that their action was necessary due to the airport’s contribution to life-threatening climatic changes and that Heathrow’s proposed expansion is inhumane to local residents and those suffering the impacts of climate change.

Facebook Twitter Pinterest Police surround the last two remaining protesters occupying the north runway at Heathrow airport on 13 July 2015. Photograph: Peter Macdiarmid/Getty Images

Barrett, an atmospheric scientist with the Massachusetts Institute of Technology (MIT), has published peer-reviewed research that concludes UK airport emissions cause about 110 early deaths a year and that would rise by 170% in 2030 if aviation capacity is allowed to grow as Heathrow and other airports would like.

Evidence will be given showing that Heathrow’s air quality is the worst outside central London, with nitrogen oxides (NOx) and other pollutants well above the legal limits.

The seven men and six women, several of whom are from the local community of Sipson, admit to occupying the north runway to protest against the airport’s expansion. Their demonstration caused long delays for passengers, with 22 otward flights cancelled.

It coincided with the publication of an Airport Commission report that recommended that a new runway should be built at Heathrow rather than at Gatwick. In December, David Cameron delayed the decision until summer 2016 over environmental concerns.

Opposition to the runway at Heathrow includes MPs, cabinet ministers and all the London mayoral candidates, as well as Boris Johnson, the London mayor.