Luxembourg's parliament yesterday moved to curtail the powers of the country's monarch, Grand Duke Henri, after he refused to sign a euthanasia bill into law.

The 60-member legislature voted 56-0, with one abstention, to amend the constitution so that bills will no longer require Henri's approval before passing into law. The vote avoided a constitutional crisis and cleared the way for Henri to "promulgate" - or formally announce - the euthanasia and assisted-suicide bill after it gets final legislative approval on December 18.

As in other parliamentary monarchies, the procedure of royal assent has become little more than a formality, but it is still required for laws to take effect.

The justice minister, Luc Frieden, said the change to the constitution let Henri continue his reign "while respecting the rules of democracy".

The law makes euthanasia and assisted suicide possible after at least two doctors have been consulted. Other than Luxembourg, which has a population of 480,000, three countries have legalised euthanasia: the Netherlands, Belgium and Colombia.

On December 2 Grand Duke Henri, who is a Roman Catholic, told the prime minister, Jean-Claude Juncker, that he could not sign the euthanasia bill. The parliament had approved the bill in a first reading on February 18 by a vote of 30-26.

Henri, 53, agreed to amend the constitution to end a standoff between him and the government.

An opinion poll at the start of this month suggested that 60% of people in the country disapproved of the grand duke's withholding of royal assent. It also recorded 69% in favour of him staying on only as a "purely ceremonial" monarch; and 70% backing the euthanasia law.

A precedent for Luxembourg's move was set in 1990, when Belgium's King Badouin found himself unable to approve an abortion law. With the king's approval, the government made him a commoner for several days and passed the law, putting him back on the throne after the legislature had enacted the bill unilaterally.