Michèle Rivasi, from the European Greens, is known for her opposition to vaccines and has sparked indignation from other French politicians.
A French MEP has sparked controversy after comparing the country's new COVID-19 certificate proposals with apartheid.
On Monday, President Emmanuel Macron announced that French citizens would need the health pass to enter "places of leisure and culture" such as cinemas from July 21.
The move to restrict venues to those that have been vaccinated or have recently tested negative is part of France's latest measures to limit infection rates.
But Michèle Rivasi, a French MEP for the European Greens, compared the extension of measures to "apartheid," a regime in South Africa with introduced segregationist laws from 1948 to 1991.
"It's apartheid in the land of human rights," Rivasi tweeted on Monday.
The comments sparked indignant reactions from several French politicians, including from the Green politician's own party.
"Words have meaning: apartheid is a political regime of fear, set up by men to kill, torture, dominate," tweeted Sandra Regol, France's Deputy National Secretary for the European Greens.
"Political criticism is useful when it is responsible, these verbal derivatives are not. As an environmentalist, we can only deplore them."
"A little respect for the women, men and children in South Africa who suffered in their flesh under apartheid," added Rachid Temal, a French senator for the Socialist Party.
"Deaths, atrocities and shattered lives ... Just a little respect," he added on Twitter.
Ian Brossat, a spokesperson for the French Communist Party, also called on politicians to "spare any references" to apartheid or the Holocaust.
Rivasi -- who is known for her opposition to vaccines -- has apologised for "shocking" people by using the term but has defended her comments.
"I denounce Macron's policy of dividing the vaccinated from the non-vaccinated," she said on Twitter.
"I apologise that, in this context of deliberate discrimination, my use of the term apartheid may have shocked some."
But Rivasi pointed to the definition of "apartheid" in the Larousse, a French-language encyclopaedic dictionary, and stood by her remarks.
In announcing the new COVID-19 measures, President Macron said maximising vaccinations was essential to prevent a further national lockdown in France.
From the beginning of August, French citizens will need a valid COVID-19 health pass to enter cafés, restaurants, and shopping centres.
The measures, which also apply to staff, include travel on aeroplanes, trains or long-distance coaches, as well as for medical establishments.
So far, around 40 per cent of the French population have been fully vaccinated against COVID-19.