France vowed drastic measures to ensure the smooth running of Euro 2016, as strikes and terror fears threaten to overshadow Europe's showcase football event, which kicks off Friday.
The action on the pitch starts when hosts France face Romania in the Stade de France in Paris at 1900 GMT, but industrial unrest and jitters over a potential terror attack have blighted the build-up to the tournament.
As train drivers vowed to disrupt services to the stadium, President Francois Hollande said he would take "all necessary measures" to ensure the championships run without a hitch.
"I will be paying close attention... and if decisions need to be made, they will be made," Hollande said. "Public services will be provided... The whole of Europe will be watching."
Transport Minister Alain Vidalies warned that striking rail workers might be ordered back to work.
Vidalies told Europe 1 radio the government would use "every tool available" to get fans to the opening match and "if we have to issue orders tomorrow (for trains to be driven), we will do so."
And Paris Mayor Anne Hidalgo promised that the rubbish that has been piling up in the capital for two days due to an ongoing strike would be collected, as hundreds of thousands of fans begin to arrive for the championships.
"Of course, all the rubbish will be collected... it is already being collected today," Hidalgo told French TV.
Up to 90,000 police and private security guards will protect players and supporters the tournament, which is taking place just seven months after coordinated Daesh attacks in Paris killed 130 people.
The massive security operation got its first real test on Thursday when superstar French DJ David Guetta gave a free performance in the fan zone at the foot of the Eiffel Tower.
Some 80,000 spectators had to pass through two checkpoints and stringent security searches.
But another threat raised its ugly head when around 250 England fans clashed with police outside a bar in the southern city of Marseille late Thursday.
Police used teargas to end the disturbances after the fans pelted officers with cans in the Vieux-Port area of the city, where England will face Russia in their high-profile opener on Saturday.
Weeks of demonstrations and industrial action in protest at the Socialist government's labour market reforms have provided a sombre backdrop to Europe's four-yearly festival of football.
Tournament organisers admitted the strikes and the rubbish piled up in Paris had "already spoiled" the atmosphere.
"The image that is being given is not the one we wanted," chief organiser Jacques Lambert said.
Hollande has refused to back down on the unions' demands to withdraw the labour reforms, arguing the measures are necessary to cut stubbornly high unemployment.
In another headache for organisers, Air France pilots have called for a four-day strike starting on Saturday, when an estimated two million foreign fans will begin arriving in earnest.
The latest round of negotiations broke down on Thursday.
But Air France chief executive Frederic Gagey promised that between 70 percent and 80 percent of flights would operate on Saturday.
France remains a top target for Daesh and warnings from the United States and Britain that the tournament could be a target have only added to the sense of nervousness.
After Thursday's successful concert, the security focus shifts to the Stade de France, where three militants blew themselves up at the start of the November 13 carnage, which also targeted a concert hall and cafes and restaurants.
Among a host of extra security measures, a new perimeter fence has been added around the venue to allow more security searches of spectators.
Interior Minister Bernard Cazeneuve said Wednesday 300 people had been barred from serving in the private security teams after vetting showed they had been radicalised.