By Michelle Martin
FRANKFURT AN DER ODER, Germany (Reuters) - The first far-right party set to enter Germany's parliament for more than a half a century says it will press for Chancellor Angela Merkel to be "severely punished" for opening the door to refugees and migrants.
The Alternative for Germany (AfD), which has also called for Germany's immigration minister to be "disposed of" in Turkey where her parents come from, could become the third largest party with up to 12 percent of the vote on Sept. 24, polls show.
That is far less than similar movements in other European countries - in France far-right leader Marine Le Pen won 34 percent of the vote in May and in the Netherlands far-rightist Geert Wilders scored 13 percent in a March election.
But the prospect of a party that the foreign minister has compared with the Nazis entering the heart of German democracy is unnerving the other parties. They all refuse to work with the AfD and no one wants to sit next to them in parliament.
Leading AfD candidate Alexander Gauland denies they are Nazis, saying others only use the term because of the party's popularity. It has won support with calls for Germany to shut its borders immediately, introduce a minimum quota for deportations and stop refugees bringing their families here.
"We're gradually becoming foreigners in our own country," Gauland told an election rally in the Polish border city of Frankfurt an der Oder.
A song with the lyrics "we'll bring happiness back to your homeland" blared out of a blue campaign bus and the 76-year-old lawyer said Germany belonged to the Germans, Islam had no place here and the migrant influx would make everyone worse off.
Gauland provoked outrage for saying at another event that Germans should no longer be reproached with the Nazi past and they should take pride in what their soldiers achieved during World War One and Two.
The Nazis ruled Germany from 1933 to 1945, during which time they killed 6 million Jews in the Holocaust and invaded countries across Europe.
The AfD could end up as the biggest opposition force in the national assembly if there is a re-run of the current coalition of Merkel's conservatives and Social Democrats (SPD) -- one of the most likely scenarios.
That would mean it would chair the powerful budget committee and open the general debate during budget consultations, giving prominence to its alternatives to government policies.
Georg Pazderski, a member of the AfD's executive board, told Reuters his party would use parliamentary speeches to draw attention to the cost of the migrant crisis, troubles in the euro zone - which the AfD wants Germany to leave - and problems related to the European Union.
"We'll have a voice when we're in parliament," he said. "We won't be an easy opposition."
He expects other parties will shun the AfD for a year or two but ultimately work with it, pointing to the regional assembly in the eastern state of Saxony-Anhalt, where the AfD and Merkel's Christian Democrats voted to set up a committee to investigate left-wing extremism.
Gauland told Reuters the AfD would call for a committee to investigate the chancellor after entering parliament: "We want Ms Merkel's policy of bringing 1 million people into this country to be investigated and we want her to be severely punished for that."
For an interactive graphic on German elections click - http://tmsnrt.rs/2h0NqCT
SUITS, NOT SKINHEADS
MPs have already changed the qualification for the ceremonial post of doyen of parliament to the longest-serving MP rather than the oldest, likely to have been an AfD member.
Sahra Wagenknecht, top candidate of the radical Left party, told Reuters it was important to look at individuals for committees but added: "I won't elect any AfD member who belongs to Bjoern Hoecke's wing and who really represents Nazi views into any position of responsibility."
Hoecke has denied that Adolf Hitler was "absolutely evil", described Berlin's Holocaust Memorial as a "monument of shame" and demanded a "180 degree turnaround" in the way Germany seeks to atone for Nazi crimes.
The justice minister said some of the AfD's programme like its demand to ban minarets is unconstitutional.
Alexander Hensel, who studied the AfD's role in regional parliaments for the Otto Brenner Foundation, said debates in state assemblies had become more polarised since the AfD arrived and some other MPs would not shake hands with the newcomers.
"The AfD's aggressive right-wing positions have intensified the debates while the tone and way people deal with each other in parliament has become noticeably rougher due to the AfD's tough rhetoric and targeted provocations," he said.
Unlike previous right-wing movements in Germany the AfD - founded in 2013 by an anti-euro group of academics - has become socially acceptable so radicalised people from the middle class feel able to vote for it alongside classic radical right-wing voters, said Manfred Guellner, head of Forsa polling institute.
"You don't vote for skinheads but you can vote for professors in suits," said Guellner, referring to the likes of Gauland, who tends to wear tweed jackets.
The AfD is unlikely to gain much more support though, said Jackson Janes, president of the American Institute for Contemporary German Studies, predicting worsening infighting over whether to aim for government or stay in opposition.
"They'll add to the yelling and screaming in the Bundestag," he said, but added: "I don't see them spreading like a cancer through society."
(additional reporting by Matthias Sobolewski and Andrea Shalal; Writing by Michelle Martin; editing by Philippa Fletcher)