In a speech at Brussels Grand Synagogue to mark the 70th anniversary of Israel's foundation, premier Charles Michel said: "No accommodation with anti-Semitism can be tolerated, whatever its form. And that also goes for my own alma mater."
Michel, 42, studied law at the Free University of Brussels. It has stood by plans to award Loach an honorary doctorate on Thursday after the 81-year-old director of 2016 Palme d'Or winner I, Daniel Blake denied accusations that his long-time support for Palestinians was in any way anti-Semitic.
The row in Belgium comes as the British Labour Party under left-winger Jeremy Corbyn, for whom Loach has been a vocal supporter, is battling allegations of anti-Semitism.