Andrea Nahles said on Sunday she would resign as the leader of Germany¡¯s Social Democrats (SPD), raising new doubts about the durability of Chancellor Angela Merkel¡¯s ruling coalition with the centre-left party.

Merkel¡¯s Christian Democrats and the SPD both bled support in last week¡¯s European elections as voters turned away from mainstream political parties, eroding support for a ruling coalition that already came close to falling apart last year.

Nahles, whose SPD is a junior coalition partner in Merkel¡¯s ruling alliance, said she would resign as party leader on Monday and step down as head of the SPD¡¯s parliamentary group on Tuesday.