An Alternative für Deutschland (AfD) politician has walked out of an interview and threatened a journalist after he was confronted with parallels between his rhetoric and that of Adolf Hitler.

An interview with Björn Höcke by the state broadcaster ZDF, recorded last week but screened on Sunday, shows the AfD politician threatening “massive consequences” to a journalist who refused to restart an interview after a series of difficult questions.

The interview started with a segment in which a number of AfD politicians were read a quotation from Höcke and asked if it was from their party colleague, the figurehead of the AfD’s hardline nationalist wing, or from Hitler’s Mein Kampf.

Five AfD delegates said they could not tell if the line “When the turning point is reached, then we Germans won’t do things by halves, we will dispose of the rubbish heaps of modernity” was from Höcke or Hitler, and one delegate said the line was more likely to be from Mein Kampf.

Höcke is his party’s lead candidate in the state of Thuringia, in the former East Germany, where polls predict the AfD gaining 20-24% of the vote in state elections on 27 October.

In May 2018, an AfD tribunal ruled that Höcke was allowed to stay in the party in spite of controversial remarks about the culture of Holocaust remembrance.

The revival of language long banished from conversations in Germany because of its association with the Nazi era has been a constant feature of the rise of the rightwing populist party, which originally grew out of protest against the decision to commit German taxpayer money to a bailout of Greece in 2013.

The previous AfD leader, Frauke Petry, in 2016 called for the term völkisch be rehabilitated and wiped of its negative connotation – only to leave the party soon after, in protest against the growing influence of Höcke’s völkisch wing of politicians following a more hardline nationalist course.

In the ZDF interview, the journalist David Gebhard asked Höcke, a former history teacher, whether his use of terms with overt Nazi associations, such as entartet (“degenerate”), Volksverderber (“corruptor of the people”) and Lebensraum (“living space”) were accidental or part of a deliberate strategy.

Höcke replied that he was in favour of politicians who expressed themselves “in original ways”, while also criticising the development of the German language and the growing influence of English.

About 10 minutes into the interview, the AfD politician’s adviser interrupted the broadcast, asking for a restart because the questions had “strongly emotionally charged” the interviewee.

Höcke complained that politicians from other parties would never been confronted with a similar Hitler comparison, seemingly using the term Altparteien – a term used by Joseph Goebbels to discredit the established “old parties” of the Weimar republic.

When ZDF refused to restart the interview, Höcke walked out, warning the journalist that he could yet become a “politically interesting person in this country”.

An essay by the author Niklas Frank, published last week in the magazine Der Spiegel, accused the AfD of using the same rhetorical manoeuvres as his father, Hitler’s governor general in occupied Poland, and cites Höcke’s likening of the Holocaust memorial in Berlin to a “monument of shame” as a prime example.