Riders from Critical Mass descended on the tunnel, which opened earlier this month, on Friday evening (April 25).
Video footage posted to social media appears to show cyclists entering the southbound entrance of the tunnel before riding through to east London.
Transport for London (TfL) has confirmed that it shut the tunnel to traffic during the protest ride.
What a great ride last night with the Critical Mass. We rode our bikes through the new Slivertown Tunnel. What a lovely experience to do this. pic.twitter.com/aOWrtUIQfn
— Miss Omar (@Auntiekay28) April 26, 2025
Critical Mass events seek to highlight the number of people who want to cycle but often struggle to do so without risking their safety.
Cyclists also said that they were angry that bikes are not allowed in the Silvertown tunnel. Instead, riders have to wait for a shuttle bus to take them across the river.
A post on Critical Mass’ Instagram reads: “Some people…were pissed off at a huge infrastructure project being given loads of their tax money without a bike lane and having to wait for a ‘bicycle bus’ to cross the tunnel in – when riding it yourself is far quicker.”
The Silvertown tunnel cost around £2.2 billion and was opened by London Mayor Sadiq Khan on April 7.
TfL has said that the shuttle will ensure cyclists can safely cross the river, claiming that buses can carry “a variety of standard and non-standard cycles”.
But some campaigners have said that the shuttle was an example of TfL “greenwashing” what is essentially a new motorway for cars and HGVs.
They have also told transport bosses that they would rather a river crossing east of Tower Bridge for cyclists.
Metropolitan Police has confirmed that officers did not attend the incident.
A TfL spokesperson said: “Cycling is not allowed in the Blackwall or Silvertown Tunnel for safety reasons.
“A cycle shuttle service operates through the Silvertown Tunnel and offers a safe connection for cyclists through the tunnel between Silvertown and North Greenwich.
“During this incident, we had to close the tunnel to all traffic until it was safe to reopen again, impacting drivers and bus passengers who would use the tunnel.”
