But Le Pen indicated Tuesday that she had no intention of doing so.
Jean-Marie Le Pen founded the far-right National Front, the party that she now leads, in 1972.
"It is a temporary measure".
Ms Le Pen had until midnight on Tuesday to repay the money.
In the latest polls, the Daily Mail reported that Le Pen is the front-runner in the first round at 25 percent, followed by former conservative prime minister Francois Fillon at 22 percent, maverick independent Emmanuel Macron at 21 percent, and socialist candidate, Benoît Hamon at 15 percent.
The European Anti-Fraud Office said previous year that Le Pen's assistant's contract stipulated that her workplace was at the EP's headquarters in Brussels, and that she was unable to prove that "she continually resided in Belgium" nor that she was "regularly present at her place of work", France24 reports.
When asked whether she would impose a similar ban in France, she avoided answering directly, saying only that France had to be "very vigilant" and to secure it borders.
The investigation however found that Le Pen's assistant was unable to prove she continually resided in Belgium, or indeed regularly worked in Brussels, as stipulated in the contract with the European Parliament. She emphasized that "people are also calling for an end to this wild and anarchic globalization, and that we are moving towards greater patriotism, to the preservation of culture, of local jobs".
The party leader repeated a promise to hold a referendum on leaving the European Union within six months if she were elected president.
The deadline has now passed for Marine Le Pen to repay €298,000 (£257,0000) to the European Parliament (EP) and she now faces a €7,000 (£5,992) monthly pay cut.
Le Pen has denied the allegations and refused to pay any of the money back. Le Pen added that she had begun a court action on the matter, but that the parliament had not waited for the judgement. They have not solved any problems, they haven't improved the situation at all.