A new ‘super sewer’ for London could cause problems for cyclists, with clashes anticipated with work on the Mayor’s new Cycle Superhighways and an influx of HGVs in the capital.

Last month the Thames Tideway Tunnel was green-lit by ministers, but it will mean closing off two sections of the east-west cycle superhighway for works; at Blackfriars and on Victoria Embankment – two of the most crucial pinchpoints on the route.

“There’s no easy way of saying it but we have planning permission,” Thames Water’s Nick Tennant. told the Evening Standard. “It’s a very congested site.”

TfL says there will still be space for cyclists to ride on the southern carriageway, and cycling commissioner Andrew Gilligan insists: “There will be no impact on the east-west superhighway — it will be maintained in segregation past the work sites.”

The 15.6-mile, 7.2-metre-wide tunnel running below the river from Acton to the Abbey Mills pumping station near Stratford is being built by Thames Water and will cost £4.2 billion.

It will be funded in part by an extra £80 a year on water bills.

Stephen Cowan, leader of Hammersmith & Fulham council, said there would be “human misery to thousands of people”.

Work at some of the major tunnelling sites could go on for up to seven years, some of it 24 hours a day and seven days a week.

Inevitably this will involve dozens of HGVs carrying materials and tunnel waste through the city day and night.

Although it aims to use river barge transport for most deliveries and transporting waste to and from the major contruction sites, Thames admits that the project will mean an average 38,000 extra HGV movements a year across the capital.

Last month we reported how TfL’s managing director for surface transport, Leon Daniels, said: “We are working closely with Thames Water to ensure that there is no impact on the superhighway. It is planned that in the event of any closures, a safe, segregated and clearly signed cycle lane will be installed to get cyclists past the works.”

But a spokesman for Thames Tideway Tunnel, which received the green light from the government last week as it was grnated planning consent, suggested that sections of the planned cycle route might even be delayed.

He said: “We are liaising closely with TfL to identify ways of working collaboratively to minimise any impacts that our construction works may have on the Cycle Superhighway. These include the option of a phased approach to the Cycle Superhighway’s construction that integrates with our own plans.”