Far-right politician Marine Le Pen would win the French presidency in a run-off election against incumbent François Hollande, according to the shock results of a poll released on Friday.

It was a fresh blow for Hollande, whose approval rating is at an all-time low of 13 percent and whose personal conduct was lacerated in a book published last week by his former partner Valérie Trierweiler, the Financial Times reported.

According to the Ifop poll, National Front leader Le Pen would beat Hollande by 54-46 percent if they were matched today in the decisive second round of the presidential election. The next election is due in 2017.

The survey confirmed earlier polls showing Le Pen leading all other contenders in the first round. But it was the first time she had been shown ahead of a mainstream candidate in the second round – a scenario regarded to date as unrealistic.

Candidates who Le Pen would beat in the first round of an election, according to the poll, include former prime ministers Alain Juppé and François Fillon and former president Nicolas Sarkozy, taking 28 percent to his 25 percent.

But the only candidate she would win against in a second round run-off is Hollande, according to the poll.

Speaking at the Nato summit in Wales, Hollande insisted that no opinion poll “however difficult” would force him to give up the five-year mandate he won in 2012.

Le Pen, for her part, told Le Monde newspaper that she was willing to be prime minister in "cohabitation" with the president. "Hollande will inaugurate the flower pots and do the commemorations," she said.

The National Front was founded by Le Pen’s father, Jen-Marie Le Pen, who has been convicted of racism and Holocaust denial in the past.