France's government is allowing trade unions to protest in Paris backtracking from an earlier police ban on the demonstration.
Interior Minister Bernard Cazeneuve personally ordered the ban but then decided to allow Thursday's protest over labour laws after an emergency meeting with the unions.
"No violence will be tolerated," said Cazeneuve on Wednesday.
The ban would have been the first outlawing of a union-organised demonstration since 1962.
Violence on the fringes of recent protests has stretched a police force already challenged by the demands of a state of emergency in place since Islamist militant attacks on Paris last November and fan violence during the Euro 2016 tournament.
The initial decision to ban the march sparked instant condemnation from lawmakers across the political divide and stirred tensions within the deeply divided Socialist Party.
Philippe Martinez, leader of the hard-line CGT union, claimed "a victory for unions" and sought to press home the advantage with a call for direct talks with Hollande over the government's plans to make it easier to hire and fire workers.
Trade unions say the proposed reforms would erode the rights of workers and want the draft bill scrapped, while the government says it is key to tackling unemployment which is running at 10 percent.
Hollande and his government are standing firm against union demands, even though opinion polls show he is France's most unpopular leader in decades.
Cazeneuve authorised a 1.5km loop around a waterway at the foot of the Place de la Bastille square.
A police union official said ensuring security would be manageable as long as officers had the authority to arrest known troublemakers on sight and to usher crowds out of the area once they had completed the circuit.
Reuters
