Boris Johnson called climate activists 'crusties'. His dad's proud to wear the title

Stanley Johnson has told an Extinction Rebellion crowd in London he backs their protest methods, maintaining that he is proud to call himself an "uncooperative crusty".

Stanley Johnson joins protesters in Trafalgar Square during the third day of an Extinction Rebellion (XR) demonstration at Westminster. Source: Press Association

The father of British Prime Minister Boris Johnson has given his endorsement to climate protesters - while hitting back at one of his son's trademark verbal barbs.

The British PM has attracted the ire of climate activists after he called them "uncooperative" crusties" in "heaving hemp bivouacs".

Extinction Rebellion-aligned protesters have established occupied sites across Westminster in a bid to demand greater action to tackle carbon emissions and increase investment in renewable energy sources.

Stanley Johnson, father of the British Prime Minister Boris Johnson, speaks at an Extinction Rebellion panel on climate change in Trafalgar Square. Source: AP

But, in direct opposition to his son, Stanley Johnson told a panel in Trafalgar Square he stands with the activists willing to disrupt in the name of climate action.

“On the point of non-cooperative crusties, I wear that badge with pride," Mr Johnson said.

“It’s one of the nicest things that has been said about me for a long time. A non-cooperative crusty, absolutely superb – do they taste good? That’s my thought, I think they do.”

Extinction Rebellion's supporters have vowed to "occupy and shut down" a London airport that connects to the British capital's global financial hub.

The group is spearheading a two-week global campaign, that kicked off Monday, with partial shutdowns of traffic in cities stretching from Sydney to New York.

Its main focus has been London, where the fast-growing group backed by Swedish teen activist Greta Thunberg, was formed by UK academics studying the effects of harmful carbon emissions on Earth.

London police reported making more than 500 arrests in the first two days of protests, including campaigners who glued themselves to the pavement and chained themselves to cars.

Police arrest an activist during Extinction Rebellion demonstrations on Whitehall in London, England. Source: Getty Images Europe

Extinction Rebellion said its "Hong Kong-style" occupation of London City Airport will involve a 'Hong Kong style' occupation of the terminal building, lying, sitting or glueing-on in front of the departure and arrivals gates," it said in a statement.

"Hundreds of participants have already signed up to nonviolently use their bodies to close the airport, and are willing to sacrifice their liberty to achieve this aim."

Extinction Rebellion wants governments to adopt policies that cut harmful emissions to a net level of zero by 2025.

Britain has set itself the target of 2050.

With AFP.