The National Front leader, who ranks third in opinion polls, spelt out the financial planning behind her campaign promises just over three months before the first round of the presidential contest on April 22.

Exploiting discontent over globalization and the debt crisis in Europe, Le Pen has sought to lure voters by detailing her plan to knock the country's bloated public deficit to zero by the end of 2017.

She said she would raise 200 billion euros ($260 billion)over five-years, in large part by restoring the autonomy of the French central bank and getting it to lend to the government at cheap rates in order to slash debt costs.

"Unlike the others, I am not trying to seduce, but to convince," said the 43-year-old lawyer, who replaced her ex-paratrooper father as party head early last year.

"When other candidates are vague on purpose, I am offering concrete proposals in complete transparency," she told a news conference at the party headquarters.

An Ifop poll on Thursday for weekly magazine Paris Match showed she could score 21.5 percent in the first round of the ballot, two percent behind incumbent Nicolas Sarkozy and 5.5 points behind Socialist frontrunner Francois Hollande.

She plans to free up almost 200 billion euros primarily by pulling out of the euro and no longer contributing to financial bailout packages for the likes of Greece and other euro zone countries.

She would also introduce a range of protectionist policies, including a 3 percent tax on imports, to finance a monthly wage rise of 200 euros for poorer workers.

Le Pen said almost 41 billion euros would be drummed up by reducing legal immigration from 200,000 people a year to 10,000.

"We will drastically reduce costs ... because it (immigration) is used by big business to encourage low wages," she said.

BUDGET LOGIC

Under her leadership, the National Front has broadened its focus from immigration and French identity to a nationalistic economic platform, widening its potential appeal but exposing it to derision over the budget logic of its program.

According to the Institut Montaigne think tank, France would stand to lose up to a million jobs and a fifth of its economic wealth if it abandoned the euro, with gross domestic product shrinking by anywhere between 6 and 19 percent over a decade.

Le Pen claims France would raise almost 87 billion euros by leaving the euro -- although she refused to explain how.

A TNS Sofres poll published in Le Monde newspaper showed 31 percent of French voters now approved of National Front thinking, up from just 22 percent a year earlier.

(Reporting By John Irish; Editing by Sophie Hares)

By John Irish and Patrick Vignal