For the second time in three days a previously unknown campaign group has brought sections of the UK's busiest motorway to a standstill.

Campaigners from Insulate Britain have pulled up at key junctions, piled out of their vehicles and glued their hands to the Tarmac, holding up thousands of vehicles and increasing pollution in the process – but why?

Insulate Britain is an environmental campaign group demanding two policy changes from the government.

They want the government to immediately promise to fund and take responsibility for the insulation of all social housing in Britain by 2025.

They also want the government to "produce within four months a legally binding national plan to fully fund and take responsibility for the full low-energy and low-carbon whole-house retrofit, with no externalised costs, of all homes in Britain by 2030".

Protesters say they will continue their sit-ins until these demands are met.

They say humanity is at a "pivotal crossroads" and that global warming is "threatening to destroy human civilisation unless urgent action is taken".

Therefore, the disruption caused to people's lives pales into insignificance when compared to the imminent threat posed.

Improving the quality of homes in "fundamental" to ensuring Britain's carbon emission, fuel poverty and water reduction targets are met, the group's website adds.

The UK's 29 million homes are the "oldest and least energy efficient housing stock in Europe", meaning vast amounts of energy are wasted heating and cooling them.

The UK is committed to keep temperature rises below 1.5C under the Paris Agreement, as well as being under a legal obligation to reduce emissions from homes to zero by 2050.

Nearly 15% of the UK’s total emissions comes from heating homes, the group adds, meaning making these properties energy efficient is a crucial part of meeting the targets.

Following this morning's action 21 protesters were arrested on the M25 in Kent.

If prosecuted for obstructing a highway they would face maximum fines of £1,000 under Section 137 of the Highways Act 1980.

Shane Collins from Insulate Britain said: "Unfortunately the other methods of writing letters, of voting once every four years, of campaigning are just not having the desired effect.

"The government, whilst it has good targets for 2050, we are not hitting the milestones to get to those targets."

Instead Shane adds we are going in "completely the opposite direction".

"There's a huge road building programme," he said. "Pretty much every airport in the country wants to expand.

"The government is giving licences to new coal fields and new oil exploration."

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