A Somerset councillor who was jailed for his role in a Just Stop Oil protest on the M25 has formally resigned, triggering a by-election.

Michael Dunk was one of two Green Party councillors elected to represent the Frome West division at the local elections in May 2022.

Mr Dunk (known affectionately as ‘Mick’) was among numerous Just Stop Oil activists who climbed gantries on the M25 in November 2022 to demand an end to new fossil fuel projects.

Mr Dunk spent Christmas in prison after being sentenced at Southwark Crown Court on December 5, 2025 to 26 months, and was ordered to pay £4,380 in costs and a victim surcharge of £228. – with a crowdfunding campaign being set up to cover his legal costs and those of his fellow jailed protesters.

Mr Dunk was subsequently released on licence and has been subject to curfews at his home address in Frome – though he was able to attend the most recent full council meeting in Bridgwater on Wednesday afternoon (July 15).

After a failed appeal against his conviction, Mr Dunk has officially stepped down as a councillor – meaning a by-election will be held later this year for his replacement.

In his resignation statement, he said: “This was certainly not an action that I took lightly, but in October of 2022 the government had decided to issue a lot more oil and gas exploration licences for the North Sea.

“All the scientific evidence suggested that this policy would have made it impossible for the UK to meet our climate change target to remain below 1.5 C of warming. Any ‘reasonable’ person would want to prevent extreme global warming in order to protect future generations allowing them to have an inhabitable planet.

“Even if I did not have children and grandchildren, I would have taken that action as my conscience would not allow me to stand back and do nothing.

“The protest lasted for four days and the safety of the travelling public below us was our primary consideration.”

Mr Dunk was arrested and charged with causing a public nuisance, refused bail and was sent to HMP Wandsworth, where he shared a cell with another gantry protester.

While his younger cell-mate (who was suffering from “climate anxiety”) was remanded there for more than six weeks, Mr Dunk was released with a tag under curfew conditions after eight days.

It took until September 22, 2025 for his case to come to court, during which time National Highways (which manages the M25) charged him in the civil court for breaking its injunction – though this latter case was subsequently dismissed.

Under the council’s constitution, anyone who has been convicted of a criminal offence and been given a prison sentence (served or suspended) of at least three months cannot remain as a councillor – leaving Mr Dunk with no choice but to stand down.

He said: “I am sadly unable to continue representing those who elected me but consider that I acted in their best interests.

“I made a stand against a government policy that was at best misguided and at worst a cynical policy to keep the oil and gas lobby happy, ensuring further donations to help keep them in power.

“This is a global climate emergency – it is impossible to overstate the seriousness of our situation.

“It is essential that the government, of whatever political persuasion, continue to take forward policies that urgently address this emergency and are at least in compliance with the CO2 reduction targets already in place.

“I want to thank the council officers and councillors who are doing all they can in difficult financial circumstances. It has been a privilege to work with them and serve those residents of Frome West whom I represented.”

Somerset Council has not confirmed how soon a by-election to replace Mr Dunk will be held.

A spokesperson said: “We have been notified of circumstances which mean that Michael Dunk has ceased to hold office as a councillor.

“The appropriate statutory and administrative processes are now being followed in relation to the resulting vacancy.

“Further information regarding the vacancy, including any electoral arrangements, will be communicated in due course.”

Until any by-election is held, all casework for residents within the Frome West division will be handled by its other sitting councillor, Martin Dimery.

Whoever wins the by-election will hold the seat for less than a year, with the next round of local elections for the whole of Somerset taking place in May 2027.