AFP - Chancellor Angela Merkel Wednesday sought to play down a row over a dinner she hosted last year for Germany's top banker, which her rivals have seized upon ahead of elections on September 27.

Senior politicians from the Social Democratic Party (SPD), which hopes to unseat Merkel in the poll, have criticised the chancellor for what they say is too close a relationship with Deutsche Bank boss Josef Ackermann.

The taxpayer-funded 60th birthday bash for Ackermann was a "bit of shamelessness," Ralf Stegner, a member of the SPD's steering committee, told Spiegel Online, slamming Merkel as "tactless."

Joachim Poss, an SPD member of parliament said Merkel's actions "crossed a boundary" while another SPD deputy, Johannes Kahrs, suggested that Ackermann should have stumped up for the party himself.

"I think he's probably got the cash," he said.

Meanwhile, Renate Kuenast, parliamentary head of the Green party, said: "The chancellor does not have the right to invite 30 people to a good dinner, with good wine, all at the taxpayer's expense."

Merkel hit back in an interview with Sat1/N24 television saying there was a "critical distance" between her and the controversial banking chief.

She said she had hosted "a dinner involving debates over the economy, culture, education and research in the context of Josef Ackermann's 60th birthday."

Her spokesman, Klaus Vater, told a regular briefing earlier: "I think there was schnitzel and white asparagus" at the dinner, which took place on April 22 last year.

Ackermann prompted the row after enthusing during a television interview that "Mrs Merkel said she wanted to do something for me and that I should invite around 30 friends to the chancellery."

"And I have to say it was a wonderful evening," Ackermann added.

The bill for the party is not known, but security alone for the prominent guests would have cost the chancellery around 2,100 euros (2,995 dollars), according to calculations by ARD television.

As an ironic editorial in Wednesday's Frankfurt Rundschau put it: "Naturally, the head of government can't just order pizzas for the 'boss' of the economy."