Thames Water has revealed what is causing major delays this week around Hampden Square.

The agency has confirmed repairs are taking place to fix a “collapsed sewer”, which has led to temporary traffic lights causing long queues on all approaches.

A spokesperson added they cannot say when it is expected to be finished but the permit started on Monday and ends on March 28.

Pictures show the central part of the roundabout fenced off with rubble and what appears to be a large drain cover removed.

On the opposite side of the road cordons are in place with cones scattered around the junction.

Times Series: Hampden Square in East Barnet.Hampden Square in East Barnet.

Times Series: Hampden Square in East Barnet.Hampden Square in East Barnet.

Times Series: Hampden Square in East Barnet.Hampden Square in East Barnet.

Times Series: Congestion on Osidge Lane near Hampden Square.Congestion on Osidge Lane near Hampden Square.

Times Series: Congestion on Osidge Lane trailing all the way back to Osidge Library.Congestion on Osidge Lane trailing all the way back to Osidge Library.