"From a point of view of getting votes, it's not useful if three party leaders are described in this way," said one of the three, a German Green Deputy, Claudia Roth.
Pauline Green, MEP for London North and leader of the Socialists, the assembly's largest group, said she had received a "grudging apology" from State Minister Ayvaz Gokdemir.
The three MPs had demanded the release of jailed Kurdish deputies during a recent visit to Ankara. Mr Gokdemir was quoted as retorting: "We are not going to release these traitors for the sake of the prostitutes of Europe who have come to us."
He denied that he had used the phrase to refer to Ms Roth, Mrs Green and the third MEP, Catherine Lalumiere, of France. The Turkish Prime Minister Tansu Ciller, has dissociated herself from the minister's remarks.