THIRTEEN activists who cut through a fence at Heathrow Airport and chained themselves together on a runway are now facing possible prison sentences.

The protesters, part of action group Plane Stupid, were found guilty at Willesden Magistrates' Court on Monday of aggravated trespass and being unlawfully airside.

Flights were cancelled after the environmentalists, who oppose Heathrow's planned expansion, built a metal tripod structure and locked themselves to it in protest on July 13 last year.

The protestors, four of whom live in West Drayton, are due to be sentenced next month.

Superintendent Andy Jones, from the Met's Aviation Policing, said: "While it is the role of the police to facilitate peaceful protest it is also our role to uphold the law and to allow businesses and the public to go about their lawful business.

"When protestors encroach into the airside environment they not only cause major disruption but also significant danger to themselves and aircraft.

"These convictions send out a clear message that such behaviour will not be tolerated.

"I appreciate that airport expansion will trigger protest but I would urge those considering such action, to do so peacefully and within the bounds of the law."

Police were called at about 3.45am to reports of suspicious activity at a perimeter fence, separating the airside operational part of the airport with the public road.

Officers found discarded bolt-cutters where the fence had been cut.

Protestors had built a tripod out of scaffolding poles and surrounded themselves with 6ft high metal fencing.

The northern runway was cleared for full operational use just after 10am.

The trial took place on January 25 and sentencing will take place on February 24.

The following were found guilty:

Rebecca Holly Sanderson, 28, of Newton Road, Machynlleth, Powys;

Melanie Strickland, 32, of Borwick Avenue, Waltham Forest, E17;

Richard Steven Hawkins, 32, of Heol y Doll, Machynlleth, Powys;

Ella Gilbert, 23, of Magdalen Street, Norwich, Norfolk;

Danielle Louise Paffard, 28, of Blenhiem Grove, Southwark, SE15;

Graham Edward James Thompson, 42, of Durlston Road, Hackney, E5;

Robert Anthony Basto, 68, of Blackborough Road, Reigate, Surrey;

Kara Lauren Moses, 33, of Heol y Doll, Machynlleth, Powys;

Cameron Joseph Kaye, 23, of Kenwood Close, Sipson, West Drayton;

Edward Thacker, 26, of Kenwood Close, Sipson, West Drayton;

Alistair Craig Tamlit, 27, of Kenwood Close, Sipson, West Drayton;

Sheila Menon, 44, of Pellerin Road, Hackney, N16;

Sam Sender, 23, of Kenwood Close, Sipson, West Drayton.