Dai Davies said the speed of the Gold State Coach creates a "perfect scenario" for those wanting to cause disruption.

He said: "The procession moves so slowly, and it's one of the rare occasions where the royals move slowly, and the route is well-publicised."

Mr Davies said recent protests at the Grand National and Snooker World Championship will be a real concern for police, adding that they "gave us an indication of what we can expect before, during and after the coronation".

Policing analyst Graham Wettone agreed that protecting the coronation will be difficult.

He said: "You've got a large area to secure, you have to secure the whole area to stop [protesters] getting on the parade route that the vehicles are going to take."

Mr Wettone said the main threat will be "smaller groups who are determined to get and be disruptive".

Just Stop Oil, the group whose members threw chalk on the table at the snooker championships on Monday, has not given specific details about its plans for the coronation.

But in a statement it vowed to "continue to disrupt sports and cultural events".

Read more:
Snooker table targeted in Just Stop Oil protest recovered - as details of activists emerge
Grand National: Animal Rising protesters say they'll try to stop race from going ahead

It is not known if Animal Rising, the group that targeted the Grand National, is planning any action over the coronation weekend.

The campaign group Republic said it will be gathering along the route at Trafalgar Square but it insisted the protest would be legal and peaceful.

Mr Davies said that early preparation and understanding the mindsets of the protesters will be critical.

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"I'd be looking at key spots, narrow spots, looking at the route and saying: 'Where's the best place I could I glue myself or chuck paint?' and I would then ensure all my units are available."

The Queen Consort's son, Tom Parker Bowles, speaking to The News Agents podcast, said: "Everyone has a right to their say.

"We live in, thankfully, a free country… If people want to protest that's their right to do so… We are all allowed to have different views and I think that makes for an interesting and civilised country."