By Simon Carraud
PARIS (Reuters) - A growing majority of French voters see Marine Le Pen's far-right National Front as a threat to democracy, but a third approve of its ideas, a Kantar Sofres-Onepoint poll showed on Tuesday.
Le Pen, who most polls see coming on top in the first round of France's presidential election, has sought to make the anti-European Union, anti-immigrant National Front less of a fringe party since she took its reins from her father in 2011.
However, 58 percent of those surveyed in the poll for Le Monde and franceinfo radio said the party was a threat to democracy. After shrinking for a decade, that number has been rising since 2013, when it stood at 47 percent.
Only 19 percent of those surveyed said they wanted Le Pen to win the May 7 presidential runoff. Most polls put her ahead of other candidates in the April 23 first round, but those same surveys consistently see her losing the run-off.
A third said they completely agreed with the National Front's ideas, a proportion that has changed little since Le Pen took over the party's leadership.
The Kantar poll found key planks of Le Pen's platform gaining little traction with voters. Only 22 percent of those polled were in favour of dropping the euro as France's currency, for example, down from 34 percent in 2011 when pollsters started asking the question.
The FN's anti-EU, anti-immigrant stance helps mark it as anti-establishment but it is also seen as a likely obstacle to its election, in particular with older voters.
It is a key part of the FN's platform, and on Tuesday Le Pen reaffirmed that, if she were elected president but voters later rejected the EU exit in a referendum, she would resign.
"What would happen if I told voters we must leave and they decided to stay?" Le Pen said at a meeting with a group of entrepreneurs. "I would quit. What else can I do? My whole project can only be carried out if we get the tools and powers back (from the EU.)"
Likewise, only 21 percent were in favour of giving employment priority to French citizens over foreigners residing legally in France, a level that has changed little in recent years.
(Reporting by Simon Carraud; Writing by Leigh Thomas; Editing by Ingrid Melander, Larry King)