Rival's warning over Angela Merkel's coalition plans

Angela Merkel's efforts to entice Germany's Social Democrats into government have hit a roadblock in the form of the opposition's top female figure.

Hannelore Kraft, the premier of Germany's biggest state with 18 million people, is often talked about as the potential Left-wing successor to Merkel.

Kraft will play an influential role this week at a gathering of 200 party officials as it considers the coalition offer. She has made it clear that the chancellor has yet to win her over.

Speaking in her home city of Dusseldorf, Kraft said political parties should not be up for sale to the "majority buyer".

Any coalition deal should come at the price of changing the terms under which Merkel ran her government, said Ms Kraft, the premier of North Rhine-Westphalia.

"Although the SPD is ready to hold talks [with Mrs Merkel's CDU], these could go in either direction," said Ms Kraft.

"We are not going to wave flags for a grand coalition."

Concerns exist in the SPD over the damage that acting as Mrs Merkel's junior partner would inflict on its electoral appeal.

Party leaders in Berlin have called on the Chancellor, who fell just five seats short of a majority, to name her terms for talks.

But provincial officials, who exercise real power in Germany's federal politics, have lined up alongside Ms Kraft to take much more hostile positions.