A RING of steel will be placed around Windsor in the run-up to the royal wedding of Prince Harry and Meghan Markle, we can reveal.

Hostile vehicle mitigation barriers – currently in place in the town centre to protect locals and visitors from potential terrorists attack – will be added to and put up on the outskirts of the town in one of the biggest security measures we have ever seen.

Thames Valley Police is overseeing the security with two of its most highly experienced officers, Assistant Chief Constable David Hardcastle and Superintendent Jim Weens leading the Force’s handling of what is undoubtedly the global social event of the year.

The Observer understands that all leave has been cancelled for police on the big day – Saturday, May 19, when Windsor castle will become the focus of the world’s attention, with more than 1,000 officers and specialised units expected to patrol the streets.

It has not been released by police as to which roads will be the check points into town, but the Observer understands Sheet Street near Queensmead School at the ‘peanut’ roundabout, King Edward VII Avenue coming in from Datchet and the Albert Road from Old Windsor will be secured. The open-top carriage procession following the St George’s Chapel wedding at 1pm travels from the castle and up to the ‘peanut’ roundabout before the couple turn left into the last stage of the Long Walk to Cambridge Gates.

More than 100,000 people are expected in the town with the Observer being told around 15,000 overseas journalists understood to be arriving.

The town will be closed to visitors if police feel the crowd is beyond a ‘reasonable capacity’ to maintain security for all.

Trains will be monitored and even stopped and people will be scanned and searched.

Assistant Chief Constable Hardcastle, strategic commander for the wedding, said: “We are proud to police the Royal Borough of Windsor and Maidenhead. The Force has a long history of policing Royal events from the annual Windsor Garter Ceremony to state visits and more recently Her Majesty the Queen’s 90th birthday.

“The wedding of Prince Harry and Ms Markle is no exception.

“We are working with our partners, local businesses and the community to deliver a safe, secure and happy event for everyone.”

A police spokesman said: “A broad range of visible security measures are in place, such us the extensive network of automatic number plate recognition technology, CCTV and hostile vehicle mitigation barriers. There are also many security measures that you can’t see. In the coming weeks and months residents, local businesses and visitors to the town can expect to see an increased police presence, with police officers, both armed and unarmed, search dogs, the mounted section, the roads policing unit and the National Police Air Service.

“On the day, visitors may be stopped and checked by roads policing officers. If travelling by train, British Transport Police will be patrolling stations and carriages. Once you arrive in Windsor there will be a screening and search regime. There will also be Royal Borough community wardens and ambassadors throughout the town centre.

“The public should be reassured and not alarmed by this, as these are all part of our measures to keep people safe.”

“Residents, local business and visitors are encouraged to continue to be vigilant, they are our extra eyes and ears.

“If you see something that doesn’t look right, let us know and we will look into your concerns fully.”

The policing operation will be amongst the largest in Thames Valley Police’s history as the celebration is expected to attract in excess of 100,000 people from around the world to Windsor.

The spokesman added: “Our officers and staff are proud to be involved in policing this national celebration, and the majority of those working on this operation will be from the Thames Valley.

“A number of other forces such as British Transport Police, the Metropolitan Police Service and Surrey Police will also be involved in this policing operation and as is standard for large scale events, we will utilise mutual aid from a number of specialist units across the country.

“Our communities can be reassured that our response to incidents and day to day policing will not be affected by the policing of the Royal Wedding.”