German Chancellor Angela Merkel's struggling rival in next month's general election attempted to revive his campaign at the weekend by attacking her euro policy at his biggest rally to date.

Peer Steinbrueck, candidate for the main opposition Social Democrats (SPD), said Merkel was hurting both Germans and the citizens of the ailing eurozone countries with an unwavering focus on enforcing budgetary rigour rather than spurring growth.

"Cuts, cuts, only cuts -- that is not going to get the (eurozone) countries out of trouble," said Steinbrueck, who served as finance minister under Merkel during her first 2005-2009 term in a left-right "grand coalition".

Blasting a yawning wealth gap in Europe's top economy, he also called for an across-the-board minimum wage in Germany, which has done without one until now.

"It's not only fairer but also makes sense economically because it creates spending power," Steinbrueck said, in a full-throated, 40-minute speech that was frequently