MORE than 100,000 Britons trapped in the path of Hurricane Rita were preparing for the worst last night as all hopes of escape faded with the monster storm bearing down on Texas.

New Orleans - already devastated by Hurricane Katrina - was the first to feel the force of Rita last night as rising waters breached the hastily-repaired flood defences.

Army teams desperately tried to hold back the waters, but the worsening conditions made flying helicopters impossible. Without their heavy lifting capacity, the task of repairing the barricades was a lost cause.

The outer bands of the category three storm lashed the Louisiana coast, with the storm's punishing winds expected to reach land early this morning.

Hundreds of thousands of people have fled northwards but many more - including more than 100,000 Britons - are stranded.

Worse still, with 100-mile tailbacks and no petrol, the authorities fear many people who have tried to escape may now find themselves trapped in the open when the 135mph winds begin.

Nearly two million people along the Texas and Louisiana coasts were urged to get out of the way of Rita, setting off an unprecedented exodus that brought traffic to a standstill across the Houston metropolitan area. Cars overheated and ran out of petrol in traffic jams lasting up to 12 hours. Some drivers gave up and turned around and went home.

"It can't get much worse, 100 yards an hour," fumed Willie Bayer, 70. "It's frustrating bumper-to-bumper."

Texas officials scrambled to reroute several inbound highways to accommodate outbound traffic, but many people were waiting so long they ran out of fuel and were forced to park.

Texas Army National Guard trucks were escorted by police to provide motorists with petrol.

Last night, the inner cities were eerily deserted. Anyone who had opted to stay put was indoors, while those who tried to escape found themselves stuck on the outskirts of places like Houston.

Weathermen offered one crumb of comfort last night.

Rita has changed course slightly, and that could spare Houston and Galveston a direct hit. But it could still plough into the Beaumont and Port Arthur area, a stretch of refineries and chemical plants about 75 miles east of Houston. The two cities have a total population of about 172,000.

Scores of petrochemical plants are situated along the Texas and Louisiana Gulf Coast in the nation's biggest concentration of oil refineries, and damage and disruptions caused by Rita could cause already-rising oil and petrol prices to go even higher. Environmentalists warned of the possibility of a toxic spill.

Plants shut down operations and hundreds of workers were evacuated from offshore oil rigs. Texas Governor Rick Perry said state officials had been in contact with plants about "taking appropriate procedures to safeguard their facilities".

Forecasters warned of the possibility of a storm surge of up to six metres, battering waves and up to 40cm of rain along the Texas and western Louisiana coast, with more than 60cm possible over the next few days as the storm moves inland into Texas and wrings itself out.

Rita brought steady rain to New Orleans for the first time since Katrina.

"Hurricane Rita is a very dangerous storm," said New Orleans Mayor Ray Nagin.

"We're not letting our guard down."

Colonel Rich Wagenaar, of the Army Corps of Engineers, said water had poured into New Orleans' lower ninth ward.

"We are trying to get boats in to make repairs," he told CNN.

"The weather's too bad to fly helicopters at this time."

He said the water level was already as high as they predicted it would be at the peak of the storm - up to 4ft higher than the normal tide.

A CNN producer on the ground said there was water "as far as the eye can see".

The Army Corps of Engineers added sandbags to shore up levees in New Orleans, and installed 18m sections of metal across some of the city's canals to protect against storm surges.

About 5,000 soldiers and National Guard members remained in the city, along with about 1,400 police officers, Nagin said.

Oliver Lucius left New Orleans with his family after Katrina and was beginning to build a life in Corpus Christi. He and his wife had found jobs and their children were enrolled in local schools. Then came Rita.

"It was just settling in that I was there for the hurricane, and then I came here," said Ariel Lucius, 13, Oliver's daughter. "Now it seems like a dream."

The usually bustling tourist island of Galveston - rebuilt after as many as 12,000 people died in a hurricane in 1900 - was all but abandoned, with at least 90 per cent of its 58,000 residents cleared out.

The last major hurricane to strike the Houston area was category three Alicia in 1983. It flooded downtown Houston, spawned 22 tornadoes and left 21 people dead.

At Houston's Johnson Space Centre, Nasa evacuated its staff, powered down the computers at Mission Control and turned the international space station over to the control of the Russian space agency.

Katrina's death toll in Louisiana rose to 832 yesterday, pushing the body count to at least 1,069 across the Gulf Coast. But workers under contract to the state to collect the bodies were taken off the streets of New Orleans because of the approaching storm.

"Katrina. It's scared everyone," said Dianna Soileau, 29, who was fleeing the refinery town of Texas City with her husband and two children.

"We don't want to be the same thing."