On 10th May 1933 the Nazis took over the offices and headquarters of the Social Democratic Party. They smashed up the Democrats’ newspaper presses, seized property and took all their money. A couple of weeks later the Nazis did the same to the Communist Party. Thus, existing political parties were destroyed, they gave up their seats in the Reichstag and dissolved themselves.
On the 14th July 1933 a new law was introduced by Hitler, the “Law against the Establishment of Parties”. It declared that the Nazi Party was the only party allowed in Germany and that no NEW political parties could be formed.
“Article I: The National Socialist German Workers’ Party constitutes the only political party in Germany.”
In the November 1933 elections, despite being the only political party, the Nazis did not get 100% of the votes. They achieved 95.2% because about 3 million people protested against the Nazis by spoiling their ballot paper (deliberately filling out the wrong sections, defacing the paper etc.)