Hundreds of people have been arrested as Extinction Rebellion (XR) protesters descended on central London for the third day of their two-week action.
The protests prompted the closure of the bridge to traffic.
Earlier in the day, some protesters glued themselves to the ground around Parliament.
Others staged a sit-in elsewhere around the perimeter of the parliamentary estate, including at the Carriage Gates.
Some XR supporters said they “jumped the barriers and ran past armed police to glue (themselves) on to the floor outside the House of Lords”.
A separate protest, carried out by XR ally Animal Rebellion, saw activists glue themselves on top of and inside a pink slaughterhouse truck parked sideways across nearby Victoria Street.
The campaigners said they were demanding “a plant-based food system as a means to mitigate the worst impacts of the climate crisis and reduce the risk of future pandemics”.
They have previously used fake blood in their demonstrations.
Protests are due to continue on Friday and the Met has imposed conditions meaning the gatherings can only take place off the main roads at Parliament Square between 8am and 7pm.
XR wants the Government to declare a climate and ecological emergency, reduce greenhouse gas emissions to net zero by 2025 and establish a “citizens’ assembly on climate and ecological justice”, and is undertaking 10 days of planned action.
Some 160 arrests were made on the first day of action on Tuesday, for offences including breaching public order conditions, obstructing the highway, obstructing police and assault on an emergency worker, while 72 people had been arrested as of 5pm on Wednesday, the majority for breaching conditions imposed on the Parliament Square demonstration.