Nicolas Sarkozy returns: Former French president takes first step back to the top in party leadership poll

Mr Sarkozy is expected to win control of the conservative Union pour un Mouvement Populaire party

For Nicolas Sarkozy, it is the first test on the road that he hopes will lead back to the Elysée Palace and the French presidency in 2017.

This vote is on a smaller scale, but it is crucial for his future ambitions – one that chooses the new head of the conservative Union pour un Mouvement Populaire (UMP) party. The members of the party, who number about 268,000, took to their keyboards yesterday to make their choice in a race that Mr Sarkozy was expected to win.

While winning would normally be enough, it is the level of victory that is most important for the former president, with the crisis-ridden UMP party needing to steady its ship. Mr Sarkozy needs a landslide victory akin to the previous occasion he ran for the party leadership in 2004, when he scored 85 per cent.

"A result below 70 per cent would be in fact a defeat for him, because he is so much the charismatic saviour. That's how he wants himself to be seen," Dominique Moïsi, of the French Institute for International Relations, told Reuters TV. "Less than that score would not do, and would be used by his opponents as absolute proof that his return is a failure."

More than 134,000 people had cast their vote by yesterday afternoon, and the final result of the vote was expected last night. The vote began on Friday night, but was disrupted by a cyber-attack on the voting website, which slowed access.

UMP officials said yesterday that the cyber-attack had been "one of the risks anticipated" and added that the process had not been hit by any more problems after around 6am on Saturday. Luc Chatel, the acting UMP head, said the party had lodged a complaint with Paris police and called the attack "organised". He insisted, however, that the turnout had been strong and that the incident would not put the validity of the vote in question.

Mr Sarkozy is facing the former agriculture minister Bruno Le Maire and MP Hervé Mariton in the vote, with Mr Le Maire seen as the stronger challenger. However, the run-up to the vote has been dogged by the number of challenges the UMP faces before it can regain its position as the party of government.

Having lost the 2012 general election to François Hollande, Mr Sarkozy has watched impatiently from the sidelines, waiting for a chance to return. He confirmed the worst-kept secret in French politics in September when he announced he would be running for the UMP leadership.

In the intervening period, the UMP has failed to mount a co-ordinated opposition to Mr Hollande and the ruling Socialist party. While Mr Hollande's ratings hit record lows because of tax rises and a failure to tackle unemployment, the UMP has been faced with legal inquiries into alleged funding irregularities – and Mr Sarkozy faces a number of investigations into alleged corruption. It is no wonder that Mr Sarkozy will hope to use his elevation to leader to re-brand the party as he prepares his drive for the presidency.

A survey last week by Odoxa opinion pollsters showed only 63 per cent of UMP supporters want Mr Sarkozy back at the helm. If Mr Sarkozy, 59, makes it through this initial vote, he faces an expected challenge for the party's presidential nomination from Alain Juppé, 69, another former UMP leader. Opinion polls suggest that Mr Juppé is more popular across France.

Another issue is the rise of the right-wing Front National party, with Marine Le Pen as its figurehead. The party has made a number of political gains and Ms Le Pen is herself due to be confirmed unopposed as the leader of the Front National at a party congress vote in Lyon today. Already Mr Sarkozy has appeared to swing towards an anti-immigration, anti-EU stance in recent interviews, as if looking to take on Ms Le Pen.

Current opinion polls suggest that Ms Le Pen would make it through to the second round of voting in the 2017 presidential vote – a source of worry for both the UMP and the Socialist party.