The European Parliament has launched a hate speech investigation into a Polish politician after he stated that "women must earn less than me".

Janusz Korwan-Mikke reasoned that this should be so because women are "weaker, "smaller" and "less intelligent". 

In 2014, he was investigated for incitement to rape over remarks he made to the European Parliament. He has also previously stated that women should not be allowed vote.

Fellow parliamentary member Iratxe Garcia Perez of the Spanish Socialist Workers' Party strongly countered his comments.

"I know it hurts and worries you that today women can sit in this house and represent European citizens with the same rights as you," she said. "I am here to defend all European women from men like you.

If found guilty, penalties range from a reprimand, to a fine and a temporary suspension.