The letter in Le Monde signed by around 100 French women writers, performers and academics deplored the wave of "denunciations" that has followed claims that producer Weinstein raped and sexually assaulted women over decades.
They claimed that the "witch-hunt" that has followed threatens sexual freedom.
"Rape is a crime but insistent or clumsy flirting is not, nor is gallantry a macho aggression," said the letter signed by women including Catherine Millet, author of the explicit 2002 memoir 'The Sexual Life of Catherine M' and French actress Catherine Robbe-Grillet.
While they admit that the Weinstein affair had its uses, calling it "necessary" in exposing how some men abuse their power, their letter goes on to say that the allegations have gone too far.
"Men have been punished summarily, forced out of their jobs when all they did was touch someone's knee or try to steal a kiss."
"Men had been dragged through the mud, they argued, for "talking about intimate subjects during professional dinners or for sending sexually-charged messages to women who did not return their attentions.
"Instead of helping women, this frenzy to send these (male chauvinist) 'pigs' to the abattoir actually helps the enemies of sexual liberty -- religious extremists and the worst sort of reactionaries," the collective of women who signed the letter said.
"As women we do not recognise ourselves in this feminism, which beyond denouncing the abuse of power, takes on a hatred of men and of sexuality."
They insisted that women were "sufficiently aware that the sexual urge is by its nature wild and aggressive. But we are also clear-eyed enough not to confuse an awkward attempt to pick someone up with a sexual attack."
Author of 'The Sexual Life of Catherine M', Catherine Millet. Photo: AFP
The letter points to the dangers of the #Metoo campaign, saying that it has led to a public accusations against individuals who, "without being given the opportunity to respond or defend themselves, were put exactly on the same level as sex offenders."
It also suggests that the situation is problematic for women.
Women are now being told to "speak in the right way, to keep quiet about what makes them angry, with those who refuse to obey regarded as traitors and accomplices!", the letter claims.
"It is the characteristic of Puritanism to borrow, in the name of a so-called general good, the arguments of the protection of women and their emancipation to bind them to the status of eternal victims, poor little things under the influence of the demon patriarchy, as in the good old days of witchcraft," they wrote.
While the women behind the letter want their peers to fight for equal salaries, they do not want them to feel "forever traumatised by a pervert on the subway, even if their actions are considered a crime. A woman could even consider it as the expression of great sexual misery or as a non-event."
The spectacle of men being forced into "public confessions... and having to rack their brains and apologise for 'inappropriate behaviour' that might have happened 10, 20 or 30 years before... recalled totalitarian societies," the letter went on.
This "puritan wave" was already bringing censorship in its wake, the women insisted, claiming that some of them had already been asked to make the male characters in their writing "less sexist", and told to tone down certain scenes to "better show the trauma suffered by female characters".
It claimed that "legitimate protest against the sexual violence that women are subject to, particularly in their professional lives," had turned into a "witch-hunt".
The campaign began in the US in response to the plethora of abuse allegations against film mogul Harvey Weinstein and was quickly copied in France, where many women used the #Balancetonporc (expose your pig) hashtag to share tales of harassment.
Other signatories of the letter included high profile French writer Abnousse Shalmani who has previously compared feminism to Stalinism, the philosopher Peggy Sastre who wants to "do away with feminism" and a porn star-turned-agony aunt.
Oscar-nominated Deneuve, 74, is best known internationally for playing a bored housewife who spends her afternoons as a prostitute in Luis Bunuel classic 1967 film, "Belle du Jour".
Deneuve has made no secret of her annoyance at social media campaigns to shame men accused of harassing women.
At the end of October Deneuve made her position clear on the recent wave of allegations and the campaign which followed.
"I do not think it's the most appropriate way to get things moving," she said. "I find that the terms being used are very excessive. I really don't think it will solve the problem."
"After 'Calling our your pig' what are we going to have, 'Call our your whore?'" she said.
Deneuve sparked an outcry last March for her fulsome support of French-based director Roman Polanski, who is still wanted in the United States for the statutory rape of a 13-year-old girl in 1977.
While his victim Samantha Geimer wants the case dropped so she can get on with her life, Deneuve told French television that "she always found the word 'rape' excessive" in the circumstances.
The French broadcasting watchdog later called her comments "retrograde".