Tony Blair was due to fly into York this afternoon to see the flooded city.

The Prime Minister made a last-minute decision to visit York, Shrewsbury and Bewdley - three of the places worst affected by the disaster enveloping England.

As he made the journey to York under leaden skies, train services were deteriorating further, marooned villagers at Naburn lost their power supplies and a business leader warned that the floods will cost many millions of pounds across York and North Yorkshire.

The Environment Agency said the River Ouse had peaked at lunchtime today at 16ft above normal, but below the top of the city's flood walls.

But another 20 mms of rain were expected this afternoon and evening.

"Our worry is that the ground is now not soaking up the rain and all the rain is running straight into the river - the catchment is at full capacity," said a spokesman.

"We do not expect it to rise above the level of the Ouse barrier, but we are closely monitoring the situation."

Askham Bryan College said that three inches of rain had fallen in the last five days. Five inches fell in October, compared with just under an inch in the whole of October last year, making last month the wettest October for 40 years.

GNER trains from the south were halted at York because of flooding at Skelton, with a fleet of buses laid on to take passengers to Darlington where services resumed to Scotland.

Adam Sinclair, of York and North Yorkshire Chamber of Commerce,, said the full costs of the floods were impossible to estimate at this stage, but would run into many millions of pounds.

"It is an extremely difficult time for all businesses in York taking into account the disruptions caused by flooding, railway safety regulations and the potential fuel crisis."

More than 150 businesses have been disrupted in York by the floods. One of the worst hit restaurants is Pizza Hut on Clifford Street, which has been closed since Monday evening, due to a power cut. Water came into the building on Tuesday and flooded the toilets, so restaurant was unable to open to the public.

Tony Weaver, manager at Pizza Hut on Clifford Street, said: "We are now under three feet of water and levels are rising as we speak. Staff have been sent to help out at the other branches in the city. We have lost a lot of stock and are unable to assess the damage until the water levels drop. I can't realistically see us being open before the end of the week."

Samantha Harding, general manager of the Queen's Hotel, which only opened 14 weeks ago, said: "We ensured all our guests had alternative accommodation yesterday but we stayed overnight. Today, though, the water was going over our wellies so we thought we had better get out.

"No rooms will be flooded, it's only the entrances and exits that are the problem," she added.

Staff are having to leave early from Argos on Bridge Street because they fear they will not get home. Although the store is not yet flooded, only a set of steps separates the store from the swollen river.

Other impacts of the flooding included:

* The closure of Jorvik Medical Practice surgery in Peckitt Street, up to and including the weekend because of flooding from the Ouse. All appointments will be seen at the Bishopthorpe Road branch. More information on 01904 635116.

* The failure of a pump which usually prevents flooding in Water Lane, Clifton, York, which cannot be fixed until the level of the Ouse drops. Water Lane has been "passable with care" at the Clifton Green end since the Burdyke pump stopped working yesterday. The pump takes water from Burdyke, a beck which flows underneath Clifton, down to the Ouse by Westminster Road.

Meanwhile, Army and Navy Stores in Fossgate reported today that waterproof footwear had been selling like hot cakes.

Spokesman Kevin Foster: "We have sold at least 30 pairs of waders and hundreds of pairs of wellies. They went in no time."

City of York Council workers are working round the clock filling sandbags to help ward off the floods.

York builders' merchants JH Walker were asked to open up at midnight last night and handed over their entire supply of sand.

Managing director Philip Daggett said: "By one o'clock they had taken our entire supply, about 70 tonnes.