France's right-wing former president Nicolas Sarkozy said on Tuesday he would be supporting the centrist Emmanuel Macron in his second-round run-off in the presidential election against far-right leader Marine Le Pen.

"I will vote for Emmanuel Macron because I believe he has the necessary experience faced with a grave international crisis ... his economic project puts the value of work as the top priority and his commitment to Europe is clear and unambiguous," Sarkozy posted on his Facebook page ahead of the second-round vote on April 24.

"We must abandon our partisan habits ... Fidelity to right-wing republican values and our governing culture must lead us to answer Emmanuel Macron's call for unity," he said.

The statement came just days after the candidate from Sarkozy's own conservative Republicans party – whom he had refused to support publicly – was eliminated in the first round of the election.

Candidate Valerie Pecresse obtained only 4.8% in the vote on Sunday. This puts the Republicans in dire financial straits because it failed to reach the 5% threshold above which election campaign spending is reimbursed by the state.

On Monday, Pecresse issued an urgent plea for donations to ensure her party's survival, saying she had personally racked up campaign debts of 5 million euros ($5.5 million).