The Italian supreme court has caused outrage after ruling that those convicted of gang rape do not have to be sentenced to jail.

Late on Thursday the court upheld a constitutional court decision to annul the jail sentence of two 19-year-old men found guilty of gang raping a 16-year-old near Rome. A lower court had ruled that jail was the only sentencing option, but the supreme court disagreed, saying judges could apply alternatives.

Critics said the ruling that prison was not automatic for group rape convictions could allow some rapists to go free. Two former equal opportunities ministers – Barbara Pollastrini from the Democratic party of the left and Mara Carfagna, a minister under the former prime minister Silvio Berlusconi – both spoke out against the decision. “This sends the wrong message,” Carfagna said.