Thousands of angry leftwing protesters took to French streets on Saturday two days after Emmanuel Macron appointed a conservative prime minister. Demonstrators accused the president of a “denial of democracy” after his decision to name the former EU Brexit negotiator Michel Barnier, 73, as leader of the government. The appointment came two months after a snap general election left France with a hung parliament formed of three roughly equal blocs – the New Popular Front (NFP), a leftwing alliance; the centre, including Macron’s Renaissance party and the centre-right; and the far-right National Rally (RN) – none of which had a majority. The mass protests had been called by the NFP’s dominant group, France Unbowed (LFI), and appeared to have widespread support on Saturday despite being shunned by some of its alliance partners and the country’s unions. Barnier, a veteran politician and member of Les Républicains (LR), whose party emerged from the election with fewer than 50 MPs – the fourth largest block in the National Assembly – has yet to choose his ministers, but has said he is prepared to include representatives of the NFP, which emerged with the most MPs in the July election. Before he was named, the NFP had threatened to lodge a motion of no confidence in any government if its chosen candidate, the 37-year-old civil servant Lucie Castets, was not named PM. The RN warned it would lodge a similar motion if she was. “Democracy is not just the art of accepting you have won but the humility to accept you have lost,” Jean-Luc Mélenchon, the LFI leader, told the Paris demonstration on Saturday in a dig at Macron. He accused the president of “stealing the election”. “I call you for what will be a long battle,” he urged protesters. LFI had called for protests in 150 towns and cities across the country; marches were held in several large cities outside the capital including Nice and Nantes. Barnier’s appointment on Thursday came after a two-month search for a PM during which Macron interviewed a number of potential candidates, including Castets. He ruled her out on the grounds that she would be unable to muster enough cross-party support to form a stable government. Saturday’s peaceful protests were seen as an opening salvo in what could be weeks or months of demonstrations. Barnier, who is in a precarious political situation, said on Saturday he did not want to get into a confrontation and hoped he could form a government taking into account all views. In his first interview on Friday, Barnier said his administration would include conservatives, as well as members of Macron’s centrist party, and said he “did not exclude” having ministers from the left. While protesters marched, Barnier was meeting potential ministers to form a government that may withstand a potential vote of no confidence. Among the PM’s first jobs will be to steer the 2025 budget bill through what is likely to be a truculent lower house. The RN, which has kept a relatively low profile in recent weeks, has said it would not back an LFI motion of no confidence in any Barnier government under certain conditions, putting the far right in the position of kingmaker. “He is a prime minister under surveillance,” Jordan Bardella, the RN leader, said on Saturday. “Nothing can be done without us.” Olivier Faure, the first secretary of the Socialist party (PS), said Macron’s decision to name Barnier PM put him in the far right’s pocket. “Macron and his friends could have chosen not to punish the NFP, to let it govern while accepting it would have to compromise because it would not have an absolute majority. Instead, he preferred to put himself under the control of the RN,” Faure posted on X. A poll by Elabe on Friday suggested 74% of French people thought Macron had disregarded the election result with 55% saying they believed he had stolen the vote. At the same time, 40% said Barnier was a good choice for PM. After meeting Barnier on Saturday, Yaël Braun-Pivet, the president of the National Assembly, said parliament was “the place for the building of compromises among republican forces to bring concrete results for the French”.