He’s well-known in the United Kingdom, and his picture has appeared on the front pages of European newspapers on a regular basis. However, as French presidential elections approach, Michel Barnier – the EU’s Mr. Brexit and a potential contender – is having a more difficult time establishing himself in his own country.

Barnier has served as French foreign, European affairs, environment, and agriculture ministers, as well as twice as a European commissioner, over the course of his 50-year political career, but he has never run for a leadership position, such as president or prime minister. Now, at the age of 70, he’s hinting that he might run against President Emmanuel Macron, a centrist, and Marine Le Pen, the leader of the far-right National Rally.

Over the past week, Barnier has appeared in French media interviews touting his four years as chief EU negotiator on Britain’s exit from the world’s largest trading bloc; all of this is encapsulated in his new book, the Great Illusion, which will be released on Thursday.

The book is billed as Barnier’s “secret Brexit diary,” but as he recounts the tortuous and technical negotiations with a British team that, according to the author, frequently appears out of its depth, he gradually establishes his political credentials from humble beginnings in France’s Haute-Savoie region.

“I’m a Savoyard and proud of it. A highlander, and I’m used to long hikes in the mountains, to be careful where I put my feet. A hike can be dangerous, and we have to keep an eye on the summit, even if it’s sometimes to see the horizon,” Barnier told France Inter radio this week.

That tenacity served him well, and it is likely to be tested again as he seeks to re-unite a conservative “The Republicans” movement that is barely a shadow of the political coalitions that once surrounded former President Nicolas Sarkozy. It is unclear whether the party will be able to mount a serious challenge to Macron or even Le Pen.

Ahead of next April’s presidential election, opinion polls predict that these two will face off in a rematch of France’s last vote, in 2017. In a second round, polls predict Macron will defeat Le Pen.

When asked if he is running, Barnier, known for his candid and sober assessment of Brexit issues, was somewhat evasive: “I’m preparing to be present, and an actor, in this presidential debate because I believe I can bring something to it.”

For the time being, the French are focused on the coronavirus crisis, and rightly so, according to Barnier. “The French people must be respected, and we must reintroduce respect into the political debate,” he said. His candidacy could be officially announced in the fall.

However, in his book, Barnier – known for his unfailing politeness – demonstrates how he has the ear of Europe’s leaders. He takes care to give mostly positive and measured assessments of those he works with, from Angela Merkel in Germany to Viktor Orban in Hungary.

Even British Prime Minister Boris Johnson, a driving force behind Brexit, which Barnier believes was a terrible mistake, is described as “pragmatic,” “more efficient than some might think,” and “not to be underestimated.”

However, Johnson’s “occasionally awkward” attempts to align himself with former US President Donald Trump may have been his most egregious blunder. “I don’t think Joe Biden will have a special relationship with Boris Johnson,” writes Barnier.

Barnier remains wary of populism – as opposed to popular sentiment, which he says should be heeded and considered – labeling Le Pen, Italian right-wing League leader Matteo Salvini, and Brexit figurehead Nigel Farage as people who “want to destroy us from the inside.”

Ahead of what could be a tumultuous election campaign, the man known for his mantra “keep calm and negotiate” faces a straightforward task: raise his profile and political credibility in France.

According to the polls, Barnier’s chances are slim. Nonetheless, previous elections have produced their fair share of surprises. Macron emerged as a credible contender only months before the last election, when the then-conservative candidate Francois Fillon, who had been a favorite, collapsed amid allegations of fraud.