Three people were arrested in connection with potential co-ordinated disruption at Aintree Racecourse as animal rights activists gathered outside the track before the Grand National Festival’s final day.

A 33-year-old woman from the London area was arrested in the Greater Manchester area on Saturday morning on suspicion of conspiracy to cause public nuisance, Merseyside Police said.

A 25-year-old woman from London and a man were arrested outside the racecourse later on Saturday morning on suspicion of conspiracy to cause public nuisance.

The race has to stop. Today and forever

The force said: “Merseyside Police has been working with The Jockey Club and other partners to keep people safe during the Grand National Festival.

“We are aware of some people planning to protest at the event. This has been factored into our plans. We respect the right to peaceful protest and expression of views, but criminal behaviour and disorder will not be tolerated and will be dealt with robustly.”

It comes after climate and animal rights group Animal Rising announced plans to scale fences and enter the track – with up to 300 activists – to prevent the race from starting.

Activists also said they would block traffic by performing a slow march along Ormskirk Road, the main access route.

About 30 animal rights protesters gathered outside Aintree Racecourse on Saturday morning.

The annual Grand National race is set to start at 5.15pm.

Dora Hargitai, 37, a volunteer with Animal Rising, said: “I do believe we can have non-violence on both sides.

“The race has to stop. Today and forever.”

Claudia Penna Rojas, from the same group, said: “We will be slow marching around the perimeter and at some point we may peacefully try to make our way towards the track, again to prevent this race from happening because we know horses are being harmed.”

She added that if activists did get onto the track it would not be while horses were running because they did not want to put them in danger.

This is very much about a bigger picture of recognising that, in a nation of animal lovers, we're not really living up to those values with our actions

One horse has died at the Grand National Festival – Envoye Special, ridden by James King – after it fell in the Foxhunters’ Chase just after 4pm on Thursday.

It is the 60th horse to die at Aintree in the past 23 years.

Animal Rising, which changed its name from Animal Rebellion on Monday to move away from the umbrella of Extinction Rebellion, wants to use UK horse racing’s biggest calendar event to highlight the “broken relationship” between humans and animals.

Spokesman Nathan McGovern said: “It’s a spotlight that we really need to be using to push a national conversation about our broken relationship, not only with horses but with all the animals that we use, whether that’s for food, fun, entertainment and dog and horse racing.

“This is very much about a bigger picture of recognising that, in a nation of animal lovers, we’re not really living up to those values with our actions.”

Animal Rising’s plans for the Grand National became public when an undercover Mail on Sunday reporter attended a meeting earlier this month. They said the activists planned to use ladders and bolt cutters to get through Aintree’s perimeter fencing.

An Aintree Racecourse spokesperson said: “We respect the right to peaceful protest but sincerely hope that Animal Rising reflect on whether their proposed actions are legitimate and responsible.

“Their actions could endanger the horses they purport to protect, as well as jockeys, officials and themselves.

“As you would expect, we are working closely with Merseyside Police to ensure we protect the safety and enjoyment of everyone, including all participants, human or equine, at the Grand National.”

A British Horseracing Authority spokesperson said: “While we respect the rights of anyone to protest safely and legally, we condemn any action which is illegal, especially if it puts at risk the safety of horses, jockeys, officials or fans.”