BERLIN (Reuters) - Frauke Petry, the former co-leader of the far right Alternative for Germany (AfD), will unveil her new “Blue Party” on Friday, promising a “reasonable conservative” agenda that would appeal to a broad base of Germans, she told a newspaper group.

FILE PHOTO - Frauke Petry, chairwoman of the anti-immigration party Alternative fuer Deutschland (AfD) speaks as she leaves a news conference in Berlin, Germany, September 25, 2017. REUTERS/Fabrizio Bensch

Petry, a 42-year-old chemist, was for a time the most visible face of the AfD, helping to build the public appeal that saw it win 12.6 percent of the vote last month and become the first far right group in the German parliament since the 1960s.

But although she has long espoused strong anti-immigrant views, she berated other leading figures in the AfD for holding positions too far outside the mainstream and making it impossible for the party to join a coalition government.

During the months leading up to the election she took a lower profile role in campaigning, all but vanishing from TV screens as more radical figures became the party’s public faces.

She won a seat in parliament on the AfD’s list last month, but quit the party the next day in a surprise announcement at its victory press conference, pledging to sit in parliament initially as an independent.

She told RND newspaper group in an interview published late on Thursday that she would hold a small initial event to announce her new Blue Party on Friday in her home state of Saxony in the former communist East.

More rallies would follow around the country from November under the banner of “Blue Change” or “Blaue Wende”, she said. Wende is the term widely used to describe the dramatic shift in German society after the fall of the Berlin Wall in 1989.

“Blue stands for conservative, but also liberal policies in Germany and in Europe,” she told RND, adding that her new group would seek to replicate the success of the Christian Social Union (CSU), the Bavarian sister party of Chancellor Angela Merkel’s conservatives, on a national level.

The CSU, part of Merkel’s conservative bloc in parliament, has taken a harder line than Merkel’s own Christian Democratic Union over immigration, but fields candidates only in Bavaria, a state that accounts for 15 percent of Germany’s population.

“Every third German would like a reasonable, conservative political offering,” she said, adding that many frustrated voters had supported the pro-business Free Democrats, the AfD or Merkel’s CDU on Sept. 24 for lack of a better alternative.

Petry said she had begun working on plans for her new party as early as August, after AfD members refused to accept her more moderate proposals at a party congress in Cologne.

RND said German election authorities listed the new party as having been founded on Sept. 17, a week before the vote.

Petry defended her decision to quit the AfD while keeping her seat won on its list, saying she would remain loyal to her voters. “The mandate doesn’t belong to the party, even if it was won with party funds,” she said.

The AfD is ostracized by all other parties, which refuse to work with it. None even wants to sit next to the AfD in parliament.