Marion Maréchal-Le Pen, niece of National Front leader and defeated presidential candidate Marine Le Pen, will not stand for reelection to the French parliament, Le Figaro reported Tuesday.
Marion was quoted by Le Parisien as saying she made a "personal choice" to "change her life" and live privately.
"The National Front. must deeply renew itself in order to rise to the historic opportunity and meet the French people's expectations", Le Pen said in a brief address to her supporters shortly after the first projections of the presidential elections' results were released.
Following her aunt's defeat in the presidential election Sunday, the party was depending on Maréchal-Le Pen to win seats in her southern region during the legislative election in June. National Front leader Marine Le Pen puts a major stake on parliamentary elections in France by announcing a new movement, Professor of the MGIMO University Evgeniya Obichkina told TASS on Monday.
It is understood she wishes to spend more time with her young daughter, the newspaper adds.
Ms Le Pen is estranged from her father, while Ms Marechal-Le Pen and him have closer ties.
In her letter, she suggested she would return to political life one day.
"This raises a lot of questions on how the party will evolve", said Joel Gombin, a specialist of the FN at the Jean Jaures research institute.
She said her relative's decision to soften her stance on seeking to quit the euro had come too late for voters concerned about that part of her programme.
Marechal-Le Pen, who is the granddaughter of National Front co-founder Jean-Marie Le Pen, is also said to be stepping down from a regional council where she leads the main opposition group.
After she lost to centrist candidate Emmanuel Macron, 39, on Sunday, she said she wanted to transform the National Front, while other party officials said an alternative name was being considered.