The group ran on to the stage during Matthew Bourne's ballet adaptation of the Shakespeare classic and unfurled a banner that said "drop Barclays sponsorship".

In video filmed by the group known as Fossil Free London, performers were seen immediately leaving the stage before the safety curtain came down, drawing a mixture of cheers and boos from the audience.

The noise from the audience appeared to try to drown out the protesters, who spent several minutes chanting "drop Barclays sponsorship".

Additional protesters could be seen in the wings holding cardboard signs - one of which demanded an end to money linked to oil in arts and culture organisations.

Protesters were then spoken to by security and the performance later continued.

A spokesperson for Sadler's Wells told Sky News: "We respect the right of individuals to air views on these matters, but a disruption to dedicated musicians and young dancers at an eagerly awaited performance during this sell-out run of Romeo and Juliet is wholly unacceptable, and we are supporting police to investigate the matter."

Spokesperson for Fossil Free London, Joanna Warrington, said: "Like doomed star-crossed lovers, Barclays and Sadler's Wells are trapped in a deadly romance as they exchange money for social acceptance, except in this version, after the worst effects of climate breakdown ricochet across the world, we all die.

"By taking their dirty money, Sadler's Wells is helping Barclays to launder its dirty image and is complicit in their climate-wrecking investments. It's time to cut oily money out of the arts."

The group claims Barclays is investing in new oil and gas projects, saying the bank has spent more than $190bn (£150bn) on fossil fuels since the Paris Climate Accord was signed in 2016.

Barclays said in a statement: "We believe that Barclays can make the greatest difference as a bank by working with customers and clients as they transition to a low-carbon business model, focussing on facilitating the finance needed to change business practices and scale new green technologies.

"This includes many oil and gas companies that are critical to the transition, and have committed significant resources and expertise to renewable energy. Where companies are unwilling to reduce their emissions consistent with internationally accepted pathways, they may find it difficult to access financing, including from Barclays."

Fossile Free London says it is a "grassroots climate group campaigning for a London beyond fossil fuels, imagining a cleaner, greener city for residents and for people worldwide who are experiencing the loss and damage of climate crises made in London".

It comes after several months of disruption aimed at sporting and cultural events, mostly in London, with group Just Stop Oil spraying paint on government buildings, covering a Wimbledon court in orange powder, and storming the Ashes.