Two Greenpeace campaigners who caused thousands of pounds worth of damage to Nelson’s Column during a publicity stunt have been spared jail.Alison Garrigan and Luke Jones scaled the pillar as dawn broke in Trafalgar Square on April 18 this year as part of a high-profile air pollution campaign targeting recognised landmarks.Westminster magistrates’ court heard that the pair, both 30, arrived at 6am before scaling the 165ft (50m) granite and bronze Grade I-listed statue commemorating Lord Nelson’s victory at the Battle of Trafalgar.The defendants placed a papier-mache mask over the figure – designed, they said, to demonstrate the serious impact of air pollution in the capital and around the globe – and caused damage to the statue’s vertical lightning conductor and its fixings by running their climbing equipment through it. She said: “Police saw them climbing, Mr Jones then Ms Garrigan, who placed a mask over the statue. They abseiled down and were arrested.”She said total damage was estimated at up to £35,000. Repairs will be incorporated within scheduled maintenance work on the statue, due to take place next year.Garrigan, from Manchester, and Jones, from Hackney, east London, both pleaded guilty to causing criminal damage.Garrigan has convictions for trespass, while Jones previously committed criminal damage and trespass. Mike Schwarz, defending, said Garrigan, a domestic violence worker, and Jones, a logistician with Greenpeace, were committed to raising the profile of the dangers of air pollution.He said: “They sought to mitigate any danger by avoiding scuffing to the column. “In terms of deliberate action, this is not a case of vandalism.”They were very careful to ensure their actions caused minimum damage while demonstrating their views.”He said a Greenpeace statement at the time said Nelson’s Column was chosen to illustrate the air pollution Admiral Nelson would have had to put up with had he been alive in London in 2016. They also flattened spikes intended to deter pigeons from settling on the statue. The pair – both skilled climbers – then abseiled to the ground, where they were arrested by police, who described the protest as “polite and peaceful”.They were each given a six-month conditional discharge and ordered to pay costs of £85, and a victim surcharge of £30. Compensation of £6,262 each would be paid for by Greenpeace, the court heard.Sentencing the pair, chairman of the bench Mike Snow said: “The defendants are both skilled climbers who, I accept, did not intend to cause damage.I accept that they took active steps to avoid damaging the structure. Greenpeace activist Alison Garrigan leaves Westminster magistrates’ courtCredit:Kirsty O’Connor/PA Wire “They plead guilty on a reckless basis and that is the basis on which I will sentence them.”The lack of intention to cause the damage is revealed by their guilty plea, the method that they adopted to execute their protest and the confirmation that Greenpeace will today pay the full amount of compensation requested.”Carly Loftus, prosecuting, told the court the offending passed the custody threshold. She said the pair arrived in Trafalgar Square with ladders, climbing equipment and leaflets before they began to scale the statue in front of a band of supporters. Greenpeace activist Luke JonesCredit:Kirsty O’Connor/PA Wire Want the best of The Telegraph direct to your email and WhatsApp? Sign up to our free twice-daily Front Page newsletter and new audio briefings.