The Grand National will be defended by a 'ring of steel' on Saturday to protect it from animal rights protesters after activists caused chaos last year

A 'ring of steel' will protect this Saturday's Grand National from disruptive animal rights protestors - with police deploying specialist undercover behaviour experts to monitor the crowds.

Senior officers are keen to avoid a repeat of scenes at last year's horse race when activists stormed the track and attempted to glue themselves to fences.

Thanks to an undercover expose by the Mail, police had been alerted to the plot by campaign group Animal Rising a fortnight earlier, and were on hand to quickly arrest more than 100 protestors.

It meant the world-famous steeplechase was delayed by just 14 minutes.

But furious trainer Sandy Thomson later blamed the 'ignorant' eco-mob for the death of his horse Hill Sixteen, which suffered a fatal fall at the first fence after going 'hyper' because of the delay.

Last week Animal Rising claimed it had suspended its horse-racing protests but Superintendent Matthew Moscrop, of Merseyside Police, said a 'ring of steel' will greet them if they do decide to swoop on the Aintree course.

He said the force would be deploying expert 'Project Servator' officers - specially trained undercover units who analyse crowd behaviour to foil attacks before they happen.

Mr Moscrop explained: 'These are behavioural detection specialists who identify people whose conduct suggests they are not there to enjoy a day at the races - criminal or antisocial - and prevent it happening.'

Grand National organisers say analysis of data from previous races and conversations with welfare organisations, such as the RSPCA, has prompted several changes to this year's race.

These include a smaller field, with the number of horses running cut from 40 to 34; an earlier start time of 4pm to help horses have safer ground when landing their jumps and a shorter run to the first fence to help slow the horses down.

Sulekha Varma, clerk of the course, told the BBC: 'The race has become faster, we've seen a higher quality horse taking part, which is great in terms of the race, but a higher quality horse has a higher cruising speed and so we've had to react to that.'

The Jockey Club also stressed the changes were not a consequence of last year's protests, saying they regularly reviewed the course and 'put the care and safety of horses and jockeys above all else.'

'The reckless actions of those who breached security to illegally gain access to the track on Grand National day have had absolutely no bearing whatsoever on the changes we are making to the race,' a spokesman added.

Mr Moscrop said the fact that the 2023 race, which is watched by 800million people worldwide, was delayed by a short period and didn't have to be cancelled was actually a 'massive success.'

He said around 60 people were currently being processed by the Crown Prosecution Service and could yet go before the courts charged with disrupting the 2023 event.

Last June Animal Rising staged a further protest at Epsom on Derby day when founder Ben Newman ran onto the track shortly after the start only to be arrested and later given a suspended prison sentence.

Since then the activist group claim they have decided against further horse racing protests, saying they are satisfied their actions had started a national conversation about racehorse welfare.

But spokesman Nathan McGovern refused to definitively rule out any action at Aintree, adding: 'Never say never. But is disrupting races going to be the most effective way to end horse racing? We think not, because we think the public has already made that decision for themselves.'

A spokesperson for Aintree said the racecourse had not been contacted directly by Animal Rising ahead of Saturday's race and that they continue to work with Merseyside Police and their own security teams to plan for all eventualities.