After long and difficult discussions, the SED and the SPD agree to an "exchange of speakers" to take place in July: fundamental questions of German politics are to be discussed at two meetings, one on each side of the border. The project is cancelled a few weeks later.
RIAS report on the failure of the SED-SPD exchange of speakers, 29 June 1966 (in German) (Source: Archiv Deutschlandradio, Broadcast: Die Zeit im Funk, Reporter: Fritz Pittelkow)
