Janusz Korwin-Mikke, who once ran to be Poland’s president, shocked Brussels last week by calling women ‘weaker and less intelligent than men’.
Nearly 200,000 people had signed the petition as of 15h CET on March 8.
Wednesday saw a surge in support for the campaign, likely linked to events marking International Women’s Day.
But European Parliament (EP) officials have poured cold water on the protest having any effect. A spokeswoman said even if there were three million signatures, the institution would be unable to remove him from his post.
There is however an inquiry into his conduct, opened by EP president Antonio Tajani after complaints from Korwin-Mikke’s fellow MEPs.
If found guilty the 74-year-old could be fined or temporarily suspended.
Korwin-Mikke said last week: “Women must earn less than men, because they are weaker, smaller and less intelligent.”
Earlier he said: “Do you know how many women are in the first hundred of chess players? I tell you, no-one.”
He caused further controversy in October 2015 when he made a Hitler salute in the EP, earning himself a 10-day suspension.