Former Polish President Lech Walesa has said German writer Guenter Grass should give up his honorary citizenship of Gdansk, having served in the Waffen SS.
Lech Walesa led the Solidarity strike in the Gdansk shipyards
The Nobel Prize-winning author shocked Germany on Saturday by admitting he had been in the notorious Nazi elite force.
Grass was born in 1927 in Gdansk, then known as Danzig. The city was also the birthplace of Mr Walesa's Solidarity movement, which undermined communism.
"The best thing would be for him to give up" the honour, Mr Walesa said.
"An uncomfortable situation has developed," he told the German newspaper Bild.
"I do not feel comfortable in that company. I do not know whether one should consider revoking the title. If it had been known he was in the SS, he would never have received the honour."
Mr Walesa is himself a Nobel peace laureate and honorary citizen of Gdansk.
Grass, a seasoned left-wing campaigner and pacifist, wrote the acclaimed anti-Nazi novel The Tin Drum.
But he told the daily Frankfurter Allgemeine Zeitung that he had been drafted at the age of 17 into an SS tank division and served in Dresden.
The port city of Gdansk features prominently in Grass's novels
Previously it was only known he had served as a soldier and was wounded and taken prisoner by US forces.
Speaking before the publication of his war memoirs, Peeling Onions, he said his silence over the years had "weighed" upon him.
"My silence over all these years is one of the reasons I wrote this book," he said. "It had to come out, finally."
Few details of the author's service were given other than that he had served in the Waffen SS Frundsberg Panzer Division after failing to get a posting in the submarine service.
The Waffen SS was the combat arm of Adolf Hitler's notorious elite force, which expanded to nearly one million members during the war.
The SS had a reputation for brutality towards soldiers and civilians in Nazi-occupied Europe. It ran the death camps in which millions of people - mostly Jews - were murdered.