Mr Mueller made his accusations after the Bundestag rejected the party’s vice-presidential candidate Albrecht Glaser for the third time.
Speaking to RT, the AfD politician said: “Yesterday was my first day in Parliament in my whole life. I took part in this and I was the co-organiser of our faction, our parliamentary group, how to behave, etc.
“And I am really a bit offended by the behaviour of the other parties because they declare themselves Democrats. What happened before: we, Alternative for Germany, had voted democratically inside the parliamentary group to put forward Mr Glazer.
“For three times the other parties – who declare themselves ‘super democratic’ – obstructed, by pure wish, the democratic vote that had been put forward before by our party.”
Other parties have condemned the decision to put forward Mr Glaser, claiming he does not reflect the spirit of German politics.
Candidates need to be approved by an absolute majority of all sitting lawmakers, though if there is a third round of voting a candidate can win election with a simple majority of more ‘yes’ than ‘no’ votes.
Despite his claims, Mr Mueller said he remained optimistic about the future collaboration with other major members of the German establishment such as Angela Merkel’s CDU or the SPD.
He added: “The policy to exclude us started to crumble and this was only the beginning.”
The AfD was first elected into the German Bundestag at the last federal elections held in September 2017 after it won 13 per cent of the vote.
While Chancellor Merkel won the seat for the fourth time she saw her overall majority crash down to 33 per cent of support.
During her victory speech, Ms Merkel conceded the losses had been mostly due to her struggle with the “extraordinary challenge” she had faced as the migrant crisis swept over Germany.