Prison sentences for Heathrow 13 activists would threaten our right to protest | Letter from John McDonnell, Caroline Lucas and others

Last month, 13 activists were tried in court for carrying out a peaceful protest against the expansion of Heathrow airport (Report, Opinion, 25 January, theguardian.com). They were found guilty of aggravated trespass, and await sentencing on 24 February.

We believe it would be unjust for these people to receive prison sentences for their actions.