Nine climate change activists from Insulate Britain have been jailed for breaching High Court injunctions designed to prevent disruptive protests.

The protest group began a wave of protests in September and has blocked the M25, other roads in London including around Parliament, roads in Birmingham and Manchester, and around the Port of Dover in Kent.

On Wednesday, nine supporters of the group were jailed at the High Court in London after they admitted breaching the injunction by taking part in a blockade at junction 25 of the M25 on October 8.

Ana Heyatawin, 58, and Louis McKechnie, 20, were jailed for three months, while Ben Buse, 36, Roman Paluch-Machnik, 28, Oliver Rock, 41, Emma Smart, 44, Tim Speers, 36, and James Thomas, 47, all received four-month sentences.

The submissions made by Ben Taylor, 37, to the court on Tuesday were described by Dame Victoria Sharp as “inflammatory” and a “call to arms”, and he was therefore given a longer sentence of six months “to deter (him) from committing further breaches”.

The judge, sitting with Mr Justice Chamberlain, said there was no alternative to custodial sentences given that the group’s actions were so serious and they had made it clear they intended to further flout court orders.

She said: “The defendants, or some of them, seem to want to be martyrs for their cause, and the media campaign surrounding this hearing appears designed to suggest this.

“We, however, have to act dispassionately and proportionately.”

The group and their supporters chanted “We are unstoppable, another world is possible”, as they were led to the cells through the dock by security officers.

Raj Chada, a solicitor at Hodge Jones and Allen law firm who supported the protesters, said: “With these prison terms, the long and honourable tradition of civil disobedience is under attack again.

“Rather than leaving courts to imprison those that raise the alarm, it should be the Government that acts to protect us against the climate crisis.”

Insulate Britain says it intends to continue with the protests, which have sparked anger among motorists and others affected by the blockades, until the Government agrees to insulate homes.

Myriam Stacey QC, representing the Government, told the court on Tuesday that the injunction banning protest activity on the M25 motorway was granted by a High Court judge on September 21.

She said it was accepted by National Highways that the protests fell into the category of “civil disobedience”, and that a National Highways official had described the action, which began on September 13 and has continued for around nine weeks so far, as “unprecedented and sustained”.

She told the court the official also described the protesters as “peaceful and compliant”, and said they are “loosely affiliated” to Extinction Rebellion.

She said the protest on October 8 began at around 8.30am, with protesters blocking two lanes, and it ended shortly after 10am when the final two protesters – who had glued themselves to the ground – were removed by police.

The High Court has so far issued five injunctions to prevent protesters from blocking roads.

They include four injunctions granted to National Highways, banning demonstrations on the M25, around the Port of Dover and on major roads around London, and one to Transport for London (TfL).

TfL was granted a civil banning order aimed at preventing protesters from obstructing traffic on some of the capital’s busiest roads.

Those who breach the injunctions could be found in contempt of court and face a maximum penalty of two years in prison or an unlimited fine.

Ms Stacey said further committal proceedings will be issued against other Insulate Britain protesters by the end of the week, relating to protests on October 27.

She also said evidence is currently being gathered to bring proceedings in relation to protests on October 29 and November 2.

So far, 161 people have been involved in the roadblock campaign and there have been more than 800 arrests.