Tristram Ricketts, the chief executive of the British Horse Racing Board, the sport's ruling body, said he hoped the race could be run tomorrow: "The preference is Monday but that depends on whether the police will give clearance.
"This is a devastating blow for racing, the punter and the country as a whole, to have one of our major national sporting events spoiled in this way. We are determined to re-stage the race as early as possible."
If tomorrow proves impossible, Saturday afternoon would be the most likely time to restage the race, which was due to be broadcast world-wide to an audience of 400 million.
The Board, the administration at Aintree, trainers and jockeys all agreed that the rescheduling of the race is the best way to avert the prospect of racing, indeed all major sporting events, becoming a regular target for terrorist threats. Today's Coca-Cola Cup Final at Wembley is the next potential victim.
Jamie Osborne, who would have ridden one of the favourites, Suny Bay, said: "The race should be re-run. We should not consider abandonment at all. They have not targeted racing, they are targeting larger issues and we should race at a later date."
Robin Cook, the Shadow Foreign Secretary and a committed racegoer, was at the track and spelt out the threat that all prominent, well-publicised events now face. "No event in the sporting calendar will be safe between now and the general election," he said. "The Aintree executive and the British Horseracing Board must look at every opportunity to stage this race within the next seven days. We must not let this race go down the plughole."
Colonel Mike Dewar, a security expert, explained the advantages of staging the race quickly. "The race will be in danger again, whenever it is run," he said. "The racecourse must now be sealed off and vital points of the track put under guard so that even if there is a further threat of disruption, it can be dealt with quickly and the race can go ahead.
"For terrorists, planting a bomb at a racecourse, particularly one which receives as much publicity as Aintree on Grand National day, it is a low- risk strategy," Dewar said.
For many, the defining image of the 1997 National will now be of the trainer Jenny Pitman sobbing as she talked to Desmond Lynam on BBC, rather than exchanging banter as is usual on this day. "These people are sick," she said. "To have to leave our horses in the stableyard was awful."
The horses were not alone, though. One stable-lad, Phil Sharp, who looks after Suny Bay, refused to join in the evacuation but instead tended to all the horses who were left stranded in the stables. He was eventually ordered by police to leave.
Most of the horses either travelled home last night or were moved to nearby Haydock racecourse. A dozen remained in the stables at Aintree.
For thousands of confused racegoers it meant being stranded in Liverpool overnight as the police instructed that no cars or coaches would be allowed to leave the track until today.
Trapped at the track overnight along with the vehicles were millions of pounds of gamblers' money in bookmakers' bags, Tote cash desks and bar tills. Paul Stephenson, Merseyside Police's Assistant Chief Constable,said: "Our first priority is the safety of all concerned but of course we are also looking at issues of security."
It is the second time in four years that the Grand National has hit trouble. In 1993 the race was declared void after being wrecked by two false starts.
At 3.15, just over half an hour before yesterday's race was due to start, the words "Operation Aintree all areas" echoed around the course's public- address system and within moments the evacuation of 60,000 racegoers from the grandstands out on to the track itself, began.
The police had closed all main roads around the course as racegoers, catering staff and security guards joined an evacuation which was orderly and efficient despite the anxiety of the circumstances. Several racegoers had to be told to abandon car-boot picnics.
At 3.45, when the 38 runners should have been lining up to take part in Britain's most celebrated horse race, the announcement was made that no attempt would be made to stage the race that day. By 4pm the area had been evacuated completely. An eerie silence fell over the course, broken only by the sound of two police helicopters.
In 1993, the infamous sagging of the starting-tape elastic which led to the voided race, although serious, became something of a joke. The implications of racing becoming a target for terrorist activity are more far-reaching. Racing is a sport which by its nature attracts large numbers of people and for that reason is always going to be a soft target.
Although betting is a triviality when possible loss of life is considered, more than pounds 70m was wagered on the National this year and if the race is ultimately abandoned the lost revenue of about pounds 600,000 will leave a sizeable hole in the annual levy that helps finance the sport.
The senior stewards' secretary, Patrick Hibbert Foy, pointed to another problem: "A crowd of 60,000 was expected and I really feel they won't come back a second time. The whole thing is a complete disaster. "
One disappointed visitor to Aintree yesterday said, "I and my family have come all the way from Bristol but we won't come again. Whoever is responsible for the bombs could just do it again. I am sure ticket receipts would be well down next year and this could affect it for years to come."
The bookmakers William Hill estimate that if the race is abandoned completely it will cost them in the region of pounds 2m in administration and advertising costs. If it is re-run, bets will stand but punters have the option of cancelling. If it is abandoned, all bets will be refunded. Bets made with the Tote, be they cash, credit, ante-post or SP have been declared null and void, with all stakes being refunded.
Timetable of chaos
2.49pm: Telephone warning, using authenticated IRA codeword, made to Fazackerley hospital in Liverpool, warning that a device would go off.
2.52: Second call to police control centre in Marsh Lane, Bootle.
3.22: Crowd of 60,000 asked to evacuate the stands to the centre of the course.
3.25: Princess Royal ushered to safety by Special Branch officers as crowd ordered to evacuate entire racecourse.
3.36: Police relay messages over the racecourse public address system telling people to get as far away from the Canal Turn as possible.
3.39: Racegoers stream in their thousands to centre of the course and to the car parks to get as far away as possible from the stands and buildings.
3.42: Public address system alerts at the course say bomb due to go off at 3.50.
3.45: Some of crowd seen climbing on fences on the course - Peter Scudamore described their actions as "vandalism".
3.46: Racing is officially abandoned.
3.58: BBC live coverage ends after outside broadcast unit, including the anchor man Desmond Lynam, is evacuated.