Far-right leader Marine Le Pen says she has secured the support of 500 elected officials necessary to stand in the French presidential election.
The National Front candidate, who is third in the opinion polls, said last week she was struggling to find enough endorsements to enable her to stand.
The latest poll, by Ifop, puts President Nicolas Sarkozy ahead for the first time in the campaign.
But it gives Socialist rival Francois Hollande victory in the second round.
According to the poll, for Europe 1 and Paris Match, Mr Sarkozy would win 28.5% of the vote in the first round on 22 April, while Mr Hollande gets 27% and Ms Le Pen 16%. Centrist candidate Francois Bayrou is on 13%.
But it suggested that Mr Hollande would win the second round in May by a margin of 54.5% to 45.5%.
Ms Le Pen had admitted last week that she was having trouble picking up the necessary 500 endorsements before this Friday's deadline, while candidates with far less popular support had relatively little trouble.
"I have my 500 signatures and therefore I will be a candidate in the presidential election," She told Reuters news agency on Tuesday. The National Front leader is expected to make an official declaration later in her electoral heartland in the Pas de Calais in northern France.