A west London campaigner, who was due to give evidence at the trial of 13 Plane Stupid protesters, has hit out at the judge's decision to not call expert witnesses.

The seven men and six women, including four from Sipson , West Drayton, cut a hole in a Heathrow Airport fence and chained themselves to railings on the north runway, beginning at around 3.30am on July 13 2015.

Their actions caused 25 flights scheduled to be cancelled, but defendants pleaded not guilty at on August 19 2015, but were found guilty on Monday, January 25 .

The defendants were relying on the defence of necessity, and argued that their actions were necessary to prevent climate change .

Nic Ferriday, of west London Friends of the Earth was called by the defendants, alongside John McDonnell , Hayes and Harlington MP and Sian Berry, Green Party London Mayoral candidate.

Mr Ferriday has said that the decision, made by District Judge Deborah Wright, to not hear from expert witnesses is “suspicious”.

He said: “Not wanting to hear evidence from experts is very suspicious - but not at all surprising.

“All the omens were that the defendants would be found guilty.

“The case was brought by the government which wants a third runway at Heathrow.

“In this way the case against 13 people could be heard by a single establishment figure, in this case Magistrate Ms Wright. Why would she want to hear ‘inconvenient’ evidence from expert witnesses?”

District Judge Wright told Willesden Magistrates Court that the evidence was “irrelevant” to the charges of aggravated trespass and entering a security restricted area of Heathrow Airport.

Speaking on day three of the trial (Wednesday, January 20) about John McDonnell giving evidence in person, she said: "It (his witness statement) gives an opinion about the debate around the expansion of Heathrow and talks about the benefits of direct action, which he says may cause short term inconvenience.

"In order to allow his evidence to be given I have to be able to say that it is relevant.

"I am therefore not going to allow Mr McDonnell to give live evidence."

Nic Ferriday (centre) protests against the third runway at Heathrow

Pollution impacts: 'Played down'

Mr Ferriday explained that his evidence would have shown how the Airports Commission’s reports on air pollution had been “slanted” and the “impacts played down” so that a third runway could go ahead.

“It would have demonstrated that the conventional democratic system with its so-called “independent” commissions, consultations does not work.

“As far as I am aware, no-one before has covered the social and political context of Heathrow and air pollution.”

In her summing up statement, DJ Wright said: “Some, if not all of the defendants are convinced that the pollutants from aviation near Heathrow are responsible for a number of deaths annually.

“I have been told by some of the defendants that 31 people die each year within a 32 kilometre radius of Heathrow because of the emissions generated by aircraft using the airport.

“I received no expert evidence in this respect but I accept and I make it clear that I do not find that the assertion is true, but I accept that the defendants believe that it is.”