But contractors are still confident of having both tunnels open on the target date of December 3, 2011.

Members of the Tyne and Wear Integrated Transport Authority were told that although a lot of work was taking place on both sides of the river – in Howdon and Jarrow – the programme of work was five weeks behind schedule.

Officer Paul Fenwick told the meeting that main contractor Bouygues Travaux Publics were now doing all they could to get back on schedule.

He said: "We are five weeks behind the programme. The contractors are trying to rectify that and new machines have arrived this week to speed up work.

"The contractors are still confident they can meet the December 3, 2011 target date."

The programme includes a target date of completing the new tunnel by December 15, 2010, with the existing tunnel being closed for a year to allow for refurbishment.

A report to the committee meeting said there would be no increase to the charge for using the tunnel until the project is complete and "users can experience the better service it will bring".

Work taking place on the Howdon side includes construction of a temporary bridge to carry the Tyne View Terrace over the tunnel during its construction, sewer diversion works, medium pressure gas main diversion and construction of the cross beams for the section of new tunnel where it crosses over the existing tunnel.

A series of temporary traffic management arrangements have been implemented to cater for the construction activity to day.