Four bridges on the River Thames have been lit up with a new artwork due to stay in place for at least 10 years.

London Bridge, Cannon Street, Southwark Bridge and the Millennium Bridge have been “transformed” with sequenced LED patterns.

Up to 15 bridges, including Westminster and Waterloo, will eventually get the same treatment to “encourage more people to enjoy the river and the riverside at night”.

Southwark Bridge, transformed to launch the first phase of Illuminated River
Southwark Bridge, transformed to launch the first phase of Illuminated River (Matt Alexander/PA)

Organisers say it “is the first time the Thames bridges have been cohesively and artistically lit” and that they consulted Historic England and the London Wildlife Trust.

Once complete, Illuminated River will stretch from Albert Bridge in the west to Tower Bridge in the east and “will be the longest public art commission in the world at 2.5 miles (4km) in length”.

US artist Leo Villareal says he is “hoping to follow in the footsteps of Monet, Turner and Whistler and reveal the truly unique, inspiring and poetic character of the Thames” with the work.

Organisers say that outdated and inefficient lighting has been replaced and the new lighting will minimise direct light spill on to the river and reduce energy consumption.

London Bridge
London Bridge (Matt Alexander/PA)

While the former lighting ran all night, Illuminated River’s LED lighting will be switched off at 2am.

Hannah Rothschild, who came up with the idea and whose foundation helped fund it, said: “This project, one of the world’s longest and most ambitious cultural commissions, will transform a snake of darkness into a ribbon of light, threading art through the heart of the city.”

London mayor Sadiq Khan said: “From the Fourth Plinth to Art On The Underground, our city has a rich heritage of showcasing public art, and I am delighted that Illuminated River is bringing more free and accessible artwork to Londoners …

“The Illuminated River will celebrate the unique architecture and heritage of our bridges, showcase creativity, boost life at night and transform the way we think about the Thames.”

Organisers said the project was a philanthropically-funded initiative, with the remaining amount (less than 2%) from a combination of the City of London Corporation (to replace out of date light fittings on London Bridge) and seed funding for the competition from the Mayor’s office.