"We must not disconnect ourselves from progress in international research in biotechnology and genetic engineering," Schröder said. The chancellor made his remarks after receiving an honorary doctorate from the Biology Department at the University of Göttingen on Tuesday.

Schröder called for "research without fetters but not without borders." He said the research methods should be explored as long as the medical potential of research with adult and embryonic stem cells hadn't been exhausted and the chance to fight incurable diseases remained.

The chancellor also stood up for stem cell researchers' moral integrity and said it was arrogant to cast doubt on the scientists' motives. He stressed that the controversial issue should be dealt with in a broad social dialogue.

A large number of Germans -- 40.6 percent -- are in favor of easing restrictions on research on stem cells from embryos, according to a recent survey. Just over 28 percent told the Wahlen research group they opposed loosening the legislation, while the rest were undecided.

"Veiled cannibalism"

But politicians from the opposition Christian Democrats (CDU) and the Social Democrat's junior coalition partner, the Greens, criticized the chancellor's comments.

The right to life of an embryo must be respected despite the scientific and economic successes that stem cell research promises, CDU parliamentarian Thomas Rachel demanded. Green party parliamentarian Volker Beck called the use of embryos for embryonic stem cells "veiled cannibalism." It must remain banned, he said.

According to Social Democrat ethics expert Rene Röspel, Schröder's remarks merely reflected the chancellor's personal opinion.

The 2002 law prohibits the production of human embryonic stem cells in Germany and imposes very limited conditions under which researchers may import them. Cells may only be used from cultures that have existed since Jan. 1, 2002. They must also have been developed from artificially created embryos that were originally meant for pregnancy and not for research.

Schröder has in the past said he was in favor of liberalizing the legislation, though not publicly.