The petition comes after a number of cases in which journalists were excluded from covering campaign events.
The petition comes after a number of cases in which journalists were excluded from covering campaign events or the anti-EU, anti-immigrant candidate herself, who faces centrist Emmanuel Macron in the May 7 runoff.
"For second-round campaigning, the National Front has decided to choose which media are authorised to follow Marine Le Pen," the petition says.
"Several outlets have had their representatives excluded from any information or any possibility to follow the National Front candidate," it adds.
The petition was signed by representatives for journalists at Agence France-Presse (AFP) and editorial staff at other major French media outlets including Le Monde and Le Figaro dailies, TF1 and BFM television channels as well as France Info radio.
"We protest in the strongest way against this hindrance to carrying out our duty to inform," the petition says.
"It is not up to political structures, whatever they may be, to decide on which outlets are allowed to exercise their democratic role in society."
The group's annual World Press Freedom Index warned of the "highly toxic" media-bashing of Trump's election campaign and Britain's Brexit referendum.