The job of keeping millions of soccer fans safe at one of the world's biggest sporting events would be enough to keep most people awake at night.

Throw in a French state of emergency due to the threat of a militant attack, as well as growing demonstrations against the government, and you would have to forgive the head of security for Euro 2016 for showing a few nerves just weeks before the tournament kicks off in Paris.

"We're not stressed. We're confident, calm and cool. The objective is to organize things well," Ziad Khoury told Reuters in an interview.

Euro 2016 starts on June 10 and runs for a month at 10 stadiums across France. About 2.5 million spectators are expected for 51 soccer matches involving 24 teams. There will also be "fan zones" for crowds watching games on big screens in major cities.

"This will be the biggest security effort for the public or private sector ever in France," said 46 year-old Khoury.

It all takes place under a state of emergency that gives extra powers to police and security forces in the aftermath of the November attacks by Islamist militants that killed 130 people in Paris and targeted multiple sites across the capital, including the national soccer stadium.

"It's a general threat, which is not specifically for the Euro, but for France, Europe and democratic societies," he said.

Violent clashes have also broken out on almost a weekly basis since March over government labor reform plans to make hiring and firing easier, stretching police forces to their limits.

"Protests happen regularly in our country, but in general when a sporting event starts, it takes over the news," said Khoury. "It's very rare that in parallel there's a lot of social demands because fewer people listen."

The organizers are drafting in 10,000 to 15,000 security staff for over 110 sites, including stadiums, team hotels and other tournament sites. High-tech equipment will be used to monitor crowds.

A first test of the standards needed for Euro 2016 will take place at the Stade de France on May 21 for the French Cup final.

On average 900 specially trained stewards with about 80 health and safety personnel as well 200 volunteers will work in conjunction with the police force for each match, although numbers will vary on the profile of games and size of stadiums.

"We're in the final countdown," said Khoury, who admits that it won't be the tournament begins that they will know if the preparations have been enough. "When it comes to security, it's not about numbers of people. It's about the quality, coordination and extra tools at your disposal."

(Reporting By John Irish; Editing by Pravin Char)