Fears that a vital bridge in Cumbria may collapse are mounting after yet more heavy rain battered the flood-stricken county.

Calva Bridge, which carries a number of communication cables, has been declared unsafe and dropped several inches.

People in Workington were told 1,000 homes north of the river would lose their telephone connections if it collapsed.

The Environment Agency warned more rain overnight could lead to further flood warnings across the Lake District and river levels are expected to peak early on Wednesday.

It is feared rising waters could bring down the bridge which crosses the River Derwent, the same stretch of water which claimed the life of Pc Bill Barker last Friday as he shepherded people from Northside Bridge. Six bridges have already collapsed, causing major transport and logistical headaches for thousands of people across Cumbria.

The already ravaged town of Cockermouth is again bracing itself for rising water levels.

The town was vuisited by David Cameron, who described the disaster as "a flood of biblical proportions". Following a tour around the Fire and Rescue headquarters in the town the Tory leader pledged to "fully support" the flood-hit community if his party won the next general election.

He said: "The cost of restoring some of these bridges and securing the infrastructure is going to come into the millions of pounds and they are going to need help, and central government needs to provide that help."

Mr Cameron visited Christ Church in Cockermouth before walking down Main Street with the Chief Constable of Cumbria Police, Craig Mackey, where hundreds of homes and businesses have been seriously damaged by floodwater. He said: "Obviously these were completely horrific floods. When you walk down Main Street in Cockermouth you can just see that it was a flood of biblical proportions and there wasn't any set of flood defences that could have really withstood what happened."

The Tory leader said: "But the most overwhelming sense you get today, a few days afterwards, is just this incredible community spirit of people coming together, helping each other and working together to sort through these problems and to try to get their lives back together and it's truly impressive and humbling to see."