This year's Extinction Rebellion protests have cost the taxpayer £37million and the figure is still rising, it emerged today.

The eco group shut down parts of London for more than a week in April and returned again this month, hitting transport routes, businesses and government offices in two weeks of mayhem.

The Met Police was forced to flood the streets with officers as they attempted to keep the protests in the approved area of Trafalgar Square.

A protester is carried around by three officers as Extinction Rebellion brought London to a standstill this month. The latest police operation has cost police £21million, it emerged today

Reinforcements were needed from around the country as it took up to eight officers each to arrest uncooperative demonstrators and hours to complete paperwork due to a policy of non-compliance encouraged by Extinction Rebellion.

Met Police Commissioner revealed today that the bill for this month's protests currently stands at £21million, and is rising. More than 1,800 people were arrested during the two weeks.

Around £6million of this month's sum was spent on officers from 38 other forces while £3.5million was spent on overtime for officers.

The £21million figure is on top of the £16million needed to deal with April's protests, when more than 1,100 people were detained.

The £37million figure is equivalent to the salaries of around 1,200 police officers. By contrast, the Met only receives £15million a year from the Mayor for its violent crime taskforce.

Police have previously said the strain of having to cope with the protests meant that officers were having to spend less time with victims of real crime elsewhere in the capital.

The group unveiled a giant octopus near Trafalgar Square during last weeks demonstrations

Police have also had to find space for 80 tonnes of equipment, including stages, sound systems and placards which they seized from demonstrators over the two weeks.

Extinction Rebellion protests: The numbers April protests saw 1,100 people arrested and cost police £16million.

This month's protests saw 1,800 arrested and cost police £21million.

Of that £21m, £6million was spent on officers from other forces, £3.5million was spent on overtime.

The money spent on policing could have paid for 1,200 new officers or trebled the budget of the violent crime taskforce. Advertisement

Met chief Cressida Dick said the amount spent on the protests meant other areas were getting a worse service. She added: This is placing horrendous strain on London and the Met.'

Among the stunts the group pulled was the occupation of bridges across the Thames, gluing themselves to banks in the City and government departments, unveiling a giant octopus and having an army of breastfeeding mothers sit in the street.

Public sympathy to the group's cause dropped after one protester was seen kicking a commuter who tried to get him off a tube train at Canning Town.

Extinction Rebellion responded to the police announcement by tweeting: 'The IMF (International Monetary Fund) warns of potentially infinite costs if the climate emergency is not addressed urgently.'

The cost is expected to rise after the protests continued this week, with topless Extinction Rebellion activists covering themselves in fake oil at the National Portrait Gallery on Sunday.

Demonstrators laid down plastic sheets and had a black liquid poured on them in protest against the gallery's sponsorship by BP.