Speaking before a crowd of some 2,600 supporters in the eastern German town of Erfurt on Wednesday evening, Björn Höcke said Alternative for Germany (AfD) "must have the ambition to become a people's party."

"The AfD cannot be content with 10 or 20 percent at the next national election," said Höcke, the chairman of the Thuringia branch of German right-wing party.

Höcke also called on the Christian Social Union (CSU) to leave the ruling coalition and break off from German Chancellor Angela Merkel's Christian Democratic Union (CDU).

'Merkel must go'

The motto of Wednesday's AfD rally was "Germany and Thuringia serve." Many AfD supporters were seen carrying placards branding politicians of several established political parties as "traitors," while others read "Help us Putin!" Slogans often seen at right-leaning rallies such as "We are the people" and "Merkel must go" also made an appearance.

Missing, however, from the demonstration was the AfD's usual soundtrack, "Wir sind wir" ("We are who we are") by Paul von Dyk. Following the use of the track at previous AfD rallies, the Berlin musician snubbed the political party and refused to give them permission to use his music.

Around 500 anti-AfD protesters also took to the streets of Erfurt on Wednesday. Police kept the two groups at a distance using barricades, and there were no reports of clashes.

Border controversy

The AfD has come under increasing scrutiny in recent weeks, with German Justice Minister Heiko Maas saying on Monday that the party was "long on its way to becoming a case" for the BfV domestic intelligence service. The agency is responsible for monitoring extremist organizations and protecting the constitution.

Maas' comments came in light of an interview given by AfD leader Frauke Petry last month in which she said Germany "must prevent illegal border crossings and even use firearms if necessary" to stem the influx of refugees entering the country.

Rise in support

Despite the torrent of criticism against the AfD, support for the right-wing party in polls has risen to 10 percent as many Germans increasingly become wary of Merkel's open-door refugee policy.

A poll published by German newspaper "Bild" on Monday found that the AfD is now ahead of the center-left Social Democrats in the state of Saxony-Anhalt, where voters go to the polling stations on March 13. The right-wing party has seen a surge of 12 points since September, leaving them with 17 percent of voters in the eastern state.

ksb/cmk (dpa, epd)