Grammens spent the immediate post-war years in prison, his war time priorities having led him to be viewed as a collaborator. During the 1958 Universal Exhibition in Brussels, an event in respect of which the French language seemed in many ways preferred overDutch, Grammans protested together with the Flemish Peoples' Movement against the francophone character of the event. Grammens again found himself arrested and convicted on account of his involvement in throwing "bitumen eggs" "(pekeieren)" at the French pavilion.