The head of safety and security at the company organising the Tour de France’s Grand Départ in Yorkshire this summer says he is “100% confident” the race’s three-day visit to the UK will pass without incident – but adds that plans are being drawn up to deal with scenarios including terrorist attacks.

The last time the Tour visited the UK, when London hosted the Grand Départ in 2007, the city was on the highest level of terrorist alert after two car bombs had been found and deactivated in the West End just a week before the race was due to start.

The incidents led to an urgent review of security ahead of the opening stage, a Prologue that took in sites such as Whitehall, Buckingham Palace, Westminster Abbey and the Houses of Parliament, which took place on the second anniversary of the July 7 bombings in 2005.

Quoted in the Daily Star today, Bob Brayshaw, a former inspector with West Yorkshire Police now working with government-backed company TDFHUB2014 Ltd, revealed “detailed planning [is] taking place” regarding the “wider threat” of terrorism for this year’s visit.

Estimates are that up to 5 million people may watch the first three days of the race from the roadside, which will see the world’s largest annual sporting event spend two days in Yorkshire before heading south for a stage from Cambridge to London.

Mr Brayshaw said: “It is an open event and somebody can just turn up on the side of the road.”

Organisers will be running online surveys to try and forecast the number attending, and they are also researching areas likely to attract particularly high concentrations of fans.

“We’ve had professional crowd management dynamics specialists engaged to give us ideas of where the ebb and flows will be so we can put our resources in the right places,” Mr Brayshaw revealed.

“We’ve also gone to local authorities who clearly know their own areas.”

Besides security-related issues, there is also the question of other aspects of crowd safety.

“If a million people stand on stage one, that’s a million people who could have medical problems, who could have all sorts of issues,” explained Mr Brayshaw.

“We need to engage with the health service, fire and rescue, police and so forth to make sure facilities are there.”

Applications closed today for the last wave of recruitment of the 10,000 Tour Makers who, together with police and private security personnel, will staff the event.

Mr Brayshaw explained that a vetting process, including police background checks, would be used “to make sure the wrong people don’t get involved.”

The July 7 attacks took place the day after London had been awarded the 2012 Olympics and besides the threat of terrorism, there were also fears that a lone protestor might seek to disrupt the event.

Police, for example, kept a close eye on London-based Neil Horan, the defrocked Roman Catholic priest who had disrupted the 2003 British Grand Prix and the marathon at the Athens Olympic in 2004.

The Games themselves passed off without major incident, although there was controversy beforehand due to missiles being placed on buildings including blocks of flats close to the Olympic Park.

Contractors G4S also admitted shortly before the event that it was understaffed, forcing the government to call in the military to help.

On the evening of the opening ceremony itself, many claimed police had used heavy-handed tactics as officers stopped a Critical Mass ride from getting close to the Olympic stadium.

In March last year, five people were found guilty of offences relating to a breach of section 12 of the Public Order Act in connection with that evening’s events.

The Tour itself has long been a target for terrorists and protestors, both in France and beyond.

The threat of terrorist action from separatists on Corsica kept the race away from the French island for decades until its first visit last July.

And more than a fortnight after the London Grand Départ in 2007, when the race crossed the Pyrenees into the Spanish region of Navarre, two small devices planted by the Basque group ETA exploded near the route shortly before the riders passed by.

Meanwhile West Yorkshire Police last week hosted a delegation of French law enforcement officers and staff from Tour owners ASO in Wakefield.

Between 40 and 50 gendarmes are expected to cross the Channel to help provide security for the event, reports the Yorkshire Post.

West Yorkshire Police assistant chief constable Mark Milsom told the newspaper: “The French have run the event for years and have a tried and tested and refined way of managing it.

“We need to make sure that there is good communication between us and them so that the planning is joined up.”

He acknowledged that achieving full control of the crowds would be “impossible,” but added, “that’s not what it’s about – it’s not a security operation, it’s a sporting event.

“When you go to France, it’s clear that they see it as an honour that the Tour comes through their town or down their street.

“This is a unique opportunity for the county and it’s about celebrating and enjoying the race and it’s a real chance for neighbourhoods to come together.”