Marine Le Pen is asked to wear a headscarf by aides of the Grand Mufti of Lebanon
The controversial presidential hopeful was in Lebanon seeking to bolster support ahead of the first round of voting in April.
But the proposed meeting with the Grand Mufti Sheikh Abdul-Latif Derian – the most prominent Sunni Muslim cleric in the country – was scrapped at the last minute.
Ms Le Pen said: "You can pass on my respects to the Grand Mufti, but I will not cover myself up.
“I have met before with Grand Imam Sheikh al-Azhar in Egypt without wearing a veil."
Marine Le Pen tells officials she will not cover up for the meeting
You can pass on my respects to the Grand Mufti, but I will not cover myself up
Marine Le Pen
A spokesman for the Grand Mufti said Ms Le Pen's aides had been informed beforehand of their requirement for her to wear head covering for the meeting in Lebanese capital Beirut.
Earlier, after talks with Lebanese Prime Minister Saad Hariri, Ms Le Pen spoke out against French policy on Syria.
She described Syrian President Bashar al-Assad as the "only viable solution" for preventing ISIS from taking power in the war-ravaged country.
She said: ”I explained clearly that Bashar al-Assad was obviously today a much more reassuring solution for France than ISIS would be if it came to power in Syria, as it has partially taken power in Libya after the disappearance of Gaddafi.”
Marine Le Pen after cancelling talks with the Grand Mufti of Lebanon
Marine Le Pen
Never far from controversy, she flew to the Middle East as French police were searching the headquarters of her Front National party as part of an investigation into "fake jobs".
Ms Le Pen faces allegations she gave parliamentary assistants fake jobs paid for out of EU funds.
French judges opened a fraud investigation after prosecutors handed the dossier over to them following a preliminary investigation of more than a year.
The party's vice-president Florian Philippot dismissed the searches as a media stunt to influence the outcome of the election.
Marine Le Pen meets Lebanese Prime Minister Saad Hariri Marion Le Pen in pictures Wed, July 27, 2016
The niece of French far-right leader Marine Le Pen has joined the military reserve and has urged "young patriots" to follow in her footsteps, take a look through her career to date,
Play slideshow AFP/Getty Images 1 of 12
French far right Front National (National Front – FN) party's Parliament member and candidate for the regional elections in the Provence-Alpes-Cote d'Azur (PACA)
He said: ”These are media-stunt searches on the day when Le Pen gets a two-point bounce in the polls.
“It's always when the system is in panic that these affairs come out."
Opinion polls predict Ms Le Pen, who wants to take France out of the European Union, is likely to get the highest score in the first round of voting but then lose to a mainstream candidate in the decisive second round vote in May.
- Russia backs Marine Le Pen for French President
- Le Pen pledges that she 'WILL NOT SUBMIT' to Merkel
- Le Pen SLAMS Hollande for leaving France on brink of 'CIVIL WAR'
- French election: Marine Le Pen has 0.01% chance of winning – analysts