In picking Barnier, Macron has put his – and France’s – fate in Le Pen’s hands | Paul Taylor

Waiting two months for a new prime minister may be standard procedure for the Belgians, Dutch, Germans or Italians, inured to extended coalition negotiations, but to the French 50 days has seemed like an insufferable eternity. This was not the way things were supposed to be in the Fifth Republic, with a constitution framed in 1958 to deliver stable parliamentary majorities for a powerful president, Charles de Gaulle. Le général must be spinning in his grave.

His distant successor in the Élysée Palace, Emmanuel Macron, spent all summer dithering over a way out of the mess he created himself when he dissolved the national assembly and called a snap election in June. The option he finally chose on Thursday, bringing Michel Barnier , a conservative Gaullist former European commissioner, foreign minister and Brexit negotiator, out of retirement at 73 to lead a government, seems unlikely to offer a stable solution.

Barnier, whose Les Républicains (LR) party finished a distant fourth in the election with just 47 of the 577 parliamentary seats, has a reputation as a consensus builder and a safe, if unimaginative, pair of hands. But his survival in government will depend entirely on the goodwill of Marine Le Pen’s far-right National Rally (RN). That makes her the kingmaker and allows her to pull the plug on Barnier, and perhaps on Macron, whenever it suits her to back a no-confidence vote.

When he dissolved parliament in June , Macron said he wanted the electorate’s “clarification” after the RN surged to first place in European parliament elections . Instead, voters delivered a hung parliament with the leftwing New Popular Front (NFP) – an alliance of socialists, greens, communists and radical leftists – as the largest bloc, but well short of a majority. The left declared victory and demanded that Macron appoint a candidate of its choice as prime minister.

The president insisted at first that no one had won. Only after weeks in denial did he acknowledge that his own centrist group, which finished second, had lost. He has since sought to avoid the political consequences of that defeat by refusing to appoint the NFP’s pick, little-known civil servant Lucie Castets. He tried instead to build an improbable coalition stretching from the mainstream conservatives to the moderate left, excluding what he calls the extremes – the RN and Jean-Luc Mélenchon’s hard-left France Unbowed (LFI) – to perpetuate his pro-business policies.

The fundamental problem is that no other party had an interest in helping the unpopular, lame-duck president complete his second term with dignity. Why risk political capital acting as a life raft for drowning Macronism? Better to stick to maximalist demands and avoid getting your hands dirty. Especially since the next government will have to make spending cuts and raise taxes to plug a yawning budget deficit that has got France into trouble with the EU.

Besides, most politicians are already fixated on the next elections, the municipals in 2026 and above all the presidential race in 2027, or perhaps sooner. Macron’s prolonged delay in naming a prime minister has fuelled speculation, denied by his staff, that he might have to resign before the end of his term. His former prime minister, Édouard Philippe, was first out of the starting blocks this week, declaring his candidacy for the presidency, whenever the election happens.

Torn between appointing a centre-left prime minister who might have reversed his flagship pension reform and a centre-right premier who might not survive a censure motion, Macron has chosen to put himself in the hands of the right, and of the RN. He hopes this will preserve his legacy of economic policies that have drawn record foreign investment and brought down unemployment, but infuriated trade unions and many ordinary French people.

The conservative LR – or what is left of the once-mighty Gaullist party after its leader, Éric Ciotti, and a small band of allies teamed up with the RN in June – has sought to assert its independence. LR presidential hopeful Laurent Wauquiez initially ruled out entering a coalition or serving in government under Macron. Whether Les Républicains will join a Barnier administration, as advocated by former president Nicolas Sarkozy, remains to be seen.

The Socialists, Greens and Communists are clinging so far to their alliance with LFI, not out of any love for the tempestuous Mélenchon, but because they are terrified of losing their town hall power bases if they break up now. So they are all likely to vote against Barnier and remain firmly in opposition.

The Socialist party is still recovering from a near-death experience after former president François Hollande embraced supply-side economics and labour market reform, and voters deserted them. Their last two presidential candidates, Benoît Hamon and Anne Hidalgo, scored 6.4% and 1.8% respectively. Few want to go back down that road.

Unlike Italy, France has no tradition of a “technical” government of non-party senior civil servants, central bankers or elder statespersons such as Mario Monti or Mario Draghi, who do the dirty work of enacting necessary but unpopular reforms before yielding to elected politicians. Some see Barnier as that kind of figure, even though he is a career politician who has remained faithful to the Gaullist movement even when it turned more Eurosceptic.

The Brexit negotiator, who managed to build and retain a consensus of the 27 EU countries throughout the tense negotiations with the UK, commands wider respect in the political class and with the electorate. But Macron only turned to him as a last resort after exploring two more high-profile alternatives.

Related: France’s voters have rejected Macron. Why is he still trying to dictate who governs us? | Rokhaya Diallo

On the centre-left, Bernard Cazeneuve, a firm-handed former Socialist interior minister and prime minister under Hollande’s presidency, known for being cool under pressure and his lawyerly courtesy, appears to have been too demanding on policy change. He had criticised Macron’s fiercely contested pensions reform that raised the retirement age to 64 from 62 and an immigration law, since gutted by the constitutional council, that sought to discriminate against foreigners in welfare entitlement.

On the centre-right, Xavier Bertrand, president of the northern Hauts-de-France region, who was health and social affairs minister under Sarkozy, appears to have been vetoed by the RN, which sees him as a hostile rival in its northern fiefdoms.

Macron may have saved his pension reform by appointing Barnier, but he has put his political survival in the hands of Le Pen, who can show statesmanship by abstaining to let a tough budget pass, then pull the plug on the government when conditions are most favourable for her presidential bid.

Barnier looks like Macron’s last card to preserve his legacy, in the hope that something turns up between now and 2027 to rescue the political centre. Don’t count on it.

• Paul Taylor is a senior visiting fellow at the European Policy Centre