POOLE Bridge's £4.7m overhaul has fallen behind scheduled, it has been confirmed.

Borough of Poole (BOP) says work has been hampered by tough ground conditions, and by unrecorded cable and obstructions from previous bridges at the same site.

However, council officials insist the project remains within budget and that contractors will be taking steps to recover lost time.

Poole Bridge closed to all traffic for nine months in September 2016 for a complete overhaul.

BOP engineering manager John Rice explained: "This is a complex project that is, as expected, presenting many challenges.

"The site team are working hard to maintain progress and work within all the constraints around the works.

"Over the next few weeks progress will become more visible as the abutments are constructed and the first sections of the deck steel work are erected."

The borough says that while onsite works are "slightly behind" the offsite fabrication work - for the new deck structure of the bridge - remains on schedule.

Because contractors are working to make up time, council officials say it is too early to confirm a completion date - although when the project started the end date was given as June 2017.

Work commenced at Poole Bridge because, according to borough engineers, both of its approach spans were failing.

The project forms part of a wider £23.3million Dorset Local Enterprise Partnership (LEP) scheme, which was secured to encourage economic growth, improve housing and create better access to and from the Port of Poole.

Explaining the project, Mr Rice said: "We are replacing the blue beams, everything above the black piles going down into the water.

"The supporting walls at each end of the bridge - the abutments - are also failing and will be replaced."

Engineers will replace the bridge's dated control systems, widen the carriageway on both approaches and construct a new, wider, shared cyclepath and footway.

Poole Bridge, spanning the narrow channel between Pool Harbour and Holes Bay, was built in 1927. It was the third bridge at the same site. The first, promoted by Poole MP William Ponsonby, was a wooden toll bridge constructed in 1834.

In 1885 this was replaced with an iron swing bridge.