Angela Merkel has confirmed that she plans to step down as leader of her conservative party after 18 years, but said she will remain German chancellor for the rest of the current parliamentary term.

Mrs Merkel’s announcement follows two state election debacles for the federal government’s “grand coalition” of her conservative Christian Democratic Union (CDU), its Bavaria-only sister, the Christian Social Union, and the centre-left Social Democrats.

The 64-year-old appeared keen to set in motion an orderly transition amid recent signs that her authority is eroding. Mrs Merkel confirmed that she will not seek any other political office after the current parliamentary term ends in 2021.

Her fourth-term government, which took office in March, has become notorious for infighting. Voters punished the governing parties in state elections on Sunday in Hesse and two weeks ago in Bavaria. Mrs Merkel has led the CDU since 2000 and has been Germany’s chancellor since 2005.

She said she sees “many more opportunities than risks” in her plan to hand over the leadership of her party at a December conference. Mrs Merkel added that she ultimately bears the responsibility for her fourth-term government’s poor start, and acknowledged there need to be changes. She said it is “time to start a new chapter”.