After the Allied invasion during the battle of Normandy, Brittany was taken on 13 August 1944 and Mordrel was forced to flee to Germany. In February 1945 Mordrel began talks with French fascist leader Jacques Doriot and his Parti Populaire Français, Mordrel acting on his own. The two sides agreed on a programme of Breton independence within a ""Swiss-like"" federation. After being briefly active in the umbrella group created by Doriot, he had to flee to Italy, where his wife died in the difficult conditions to which the couple on the run was reduced to. Seeing no way out, he gave himself up to the American army. He was detained and interrogated for several months by the secret service. He saved his life by telling everything he knew of his fellow Breton separatists, the members of the Irish Republican Army and relations with different German secret services. In an agreement with the head of the British secret services, he was released but was officially declared to have escaped from prison because the new French authorities claimed him for execution. Again “on the run”, but with the backing of the American secret services, he found refuge in Brazil, then Argentina, and finally in Francoist Spain. He was again sentenced to death "in absentia", in June 1946, but continued to contribute material to the magazine "Ar Vro" as "Brython".