When Germany invaded Norway in April 1940, Quisling marched into the Norwegian Broadcasting Corporation studios in Oslo and made a radio broadcast proclaiming himself Prime Minister and ordering all anti-German resistance to end immediately. However, King Haakon VII, in unoccupied territory along with the legitimate government, let it be known he would abdicate rather than appoint any government headed by Quisling. The existing government refused to step down in Quisling's favour or serve under him, and confirmed that resistance was to be continued. With no popular support, the German forces of occupation quickly thrust Quisling aside. In April 1940 the party probably only had a few hundred members, but membership rose to 22,000 in December the same year, and peaked with 43,400 in November 1943.