Ken Livingstone is by far the best-qualified candidate to run London, and even more so from an environmental perspective argues Mark Lynas.

The Greens can justifiably claim to be the largest progressive party in the UK, but often meet with suspicion from the left. Are they given a fair hearing? Alex Nunns weighs the evidence

Mary Mellor poses some socialist questions for the Greens, and considers whether Green really is the new Red.

Peter Tatchell argues the Greens are now the only credible radical left-wing alternative and the best hope for advancing a progressive political agenda.