France will not be turned into "liberal England', Emmanuel Macron has been warned, as clashes broke out in protests against loosening labour regulations seen as a key public test of the president's reformist resolve.

Stone-throwing protesters in Paris clashed with police who responded with tear gas as some 4,000 strikes were called around France by the country's biggest public sector trade union, the hardline CGT.

Rail workers, students and civil servants were urged to protest in cities from Paris to Toulouse. By mid-afternoon, the CGT had already deemed the protests a "success", with at least 100,000 in force in provincial France and 60,000 in Paris. Police said there were 24,000 protesters in Paris. The numbers were, however, well below protests against another labour reform last year.

Hundreds of masked protesters dressed in black clashed with police in Paris, who responded with tear gas and water cannons.