Ditlev-Simonsen, from the Conservative party, invited both the former and present US ambassadors and the British ambassador to his Oslo home for dinner, reports newspaper VG.

One of the dinners, held in February of last year, was catered by the exclusive Oslo restaurant Feinschmecker and cost NOK 14,290 (around USD 2,300) for 14 guests. The guest list included both the British and American ambassadors, wealthy businessman and art collector Hans Rasmus Astrup, real estate mogul Christian Ringnes and his wife and tobacco heir Johan Andresen and his wife.

The other dinner, held in August, was catered by another top Oslo restaurant, Oro, and cost NOK 17,465. Guests there included the new US ambassador, Astrup again, shipowner Wilhelm Wilhelmsen and his wife, the city's cultural chief Gro Balas and her husband (who's Norway's ambassador to Germany), and some lesser-known names like Inggerd Bull and Mogens and Agno Mathiesen.

Ditlev-Simonsen admitted that Bull and the Mathiesens are his personal friends, "Oslo residents who I thought it would be interesting for the ambassador to meet."

He called it "common hospitality" to host an occasional dinner for an ambassador, and said he sees no problem with having taxpayers foot the bill.

Others do. For one thing, the dinner bills amounted to around NOK 1,400 per person, nearly double the per-person guideline of NOK 880 set by the state for representative affairs. "It's up to the individual townships to decide how to handle this, but I would think the state guidelines should be the guide," said state auditor general Jørgen Kosmo, the former president of the Norwegian parliament from the Labour Party.

City Councilman Knur Even Lindsjørn from the Socialist Left, meanwhile, didn't think the mayor's guest list was very representative of Oslo's population. He claimed Ditlev-Simonsen invited "the wealthy portion" of Oslo's population, while he would have preferred that the ambassadors also met "those who don't live on the sunny side."

It's not the first time Ditlev-Simonsen has faced questions over the appropriateness of his hospitality. He faced criticism a few years ago for allowing his fellow high school graduates to use City Hall for an anniversary party.