Nottinghamshire County Council said the incident was declared "due to rising levels along the River Trent" and that residents who live in flood risk areas should be prepared to evacuate their homes.

The council added that the latest forecasts were showing that peaks along the River Trent could "come close to the highest levels on record from the year 2000".

Meanwhile, the Met Office's yellow weather warning for rain across the south of England has been in place from 12pm today, lasting until 3am on Friday.

All rail services are warning passengers of delays and cancellations due to the severe conditions.

Rainfall is expected to travel in a northeast direction across the south of England, with the potential for communities to be cut off by flooding.

The Met Office said: "The track of the heaviest rainfall remains very uncertain, but there is a chance of 20 to 30 millimetres falling in six to nine hours across a portion of the warning area, with a few places perhaps seeing 40 to 50 millimetres."

The yellow weather warning comes after Storm Henk battered the UK with strong winds and rain, leaving the ground saturated and more prone to flooding in some areas, according to forecasters.

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Follow live: Flooding across England as county declares major incident

Urging people to be prepared to evacuate due to the flooding, Nottinghamshire County Council said in its statement: "Key tributaries which feed in to the River Trent, including the River Derwent, the River Soar and the River Dove, have already reached their peaks and high water levels will now pass down the Trent, which is likely to lead to the flooding to properties and roads.

"Residents who live in the flood risk areas are being asked to ensure they have preparations in place in case they are asked to evacuate. Councils, emergency services and the Environment Agency have been providing emergency support to communities impacted and will continue to provide support across the county."

It comes as a man stranded on his shed roof by floodwater in Nottinghamshire was rescued by a fire crew who used a boat to bring him safely to land.

'Outside their front doors it's like a river'

Meanwhile, several residents of Radcliffe Residential Park, an estate of static caravans for the over-55s just to the east of Nottingham in the East Midlands, had to be evacuated due to high water levels.

Laurie Walker, chairman of Radcliffe Park Residents' Association, said: "I've had someone knock on my door to say the water is going to rise another 25cm. Outside their front doors, it's like a river, I don't know if the homes have been flooded.

"To come out of the park I've had to walk through somebody else's garden to avoid the flood on the road. It's the worst it's ever been, I've been here seven years. It's a mess."

Pub landlord in tears after business floods

Parts of Worcestershire, the West Midlands, Bedfordshire, Gloucestershire, Leicestershire and West Sussex have also been flooded.

Mario Thomas, 65, landlord of The Boat Inn in Jackfield, Shropshire, has said he broke down in tears after "evil" floodwaters devastated his pub.

He said the water was up to his chest when he entered the pub close to the River Severn.

Police refers itself to watchdog after woman's death

Meanwhile, Thames Valley Police has referred itself to the police watchdog over the death of an 87-year-old woman in Oxfordshire who crashed into a tree.

The force said it received a report about the tree around 90 minutes before the collision.

Rail disruption

Great Western Railway (GWR) advised travellers against starting their journeys by rail on Thursday afternoon because of "heavy rainfall forecast on already flooded ground".

The train operator said its direct route between Swindon and Bristol Parkway remained closed because of flooding on tracks due to Storm Henk earlier in the week.

GWR said that Network Rail had identified "key sites in Wiltshire, Somerset, Devon and Cornwall as being at risk of flooding" from about 3pm on Thursday, adding that "trains may not be able to operate through these areas".

It added that these "most at risk" locations included sites between Swindon and Bristol Temple Meads via Chippenham and Bath Spa, Newton Abbot and Plymouth, Exeter and Tiverton Parkway, Bristol Temple Meads and Weston-super-Mare, and Taunton and Westbury.

It comes as South Western Railway (SWR) said "extreme rainfall" forecast in the south of England meant that customers should expect "severe disruption on the south coast, south of Guildford and west of Basingstoke" from 1pm to 7pm on Thursday.