The Prussian government, under the influence of General Joseph Maria von Radowitz, who sought to unite the landed classes against the threat to Junker domination, seized the opportunity to initiate a new German federation under the leadership of the Hohenzollern monarch.

A year before the convention of the Erfurt Union Parliament, on May 26, 1849, the Alliance of the Three Kings was concluded between Prussia, Saxony and Hanover, the latter two of which explicitly made the reservation of departure unless all other principalities with the exception of Austria joined.

150 former liberal deputies to the German national assembly had acceded to the draft at a meeting in Gotha on June 25, 1849, and by the end of August 1849, almost all (twenty-eight) principalities had recognised the Reich constitution and joined the union, due in varying degrees to Prussian pressure.

No government in the end agreed to the constitution, and even though the document was readily accepted by the Gotha Party (incidentally narrowly defeated in the elections), it never took effect.

Meanwhile, Austria, having overcome its difficulties – the fall of Metternich, the abdication of Ferdinand I, and constitutional revolts in Italy and Hungary – began a renewed active resistance against Prussia's union plan.