A road could remain closed until the middle of next week as contractors replace a sewer blocked with concrete.

Hertfordshire County Council closed Watling Street in Radlett yesterday to allow Thames Water to carry out emergency work to replace the damaged pipe.

However investigations have revealed the damage is more serious than previously thought, meaning the road could be closed until at least Tuesday.

The water company today carried out a CCTV survey to ascertain the extent of the damage, which is believed to have been caused by careless contractors. 

Councillor Terry Douris, who has responsibility for highways for Hertfordshire Council, said: "We are extremely frustrated this situation has arisen due to what appears to be someone’s irresponsible actions and residents affected by this disruption have our sympathy. Due to the nature of these works council taxpayers will not be footing the bill.

"All parties are working as hard as they can to minimise the disruption in the area. It is frustrating that the closure needs to be in place longer but due to the nature of the blockage it is essential that all of the problems are investigated and resolved while contractors are on site."