Stockholm: Sweden's parliament on Wednesday passed a law that will make it easier for people to change their legal gender and lower the age at which it is allowed to 16 years from 18 years, despite heavy criticism from within the government coalition.

Swedes have been able to change legal gender since 1972, but it can take many years and requires a thorough investigation and a doctor's diagnosis of gender dysphoria.

Under the new law, which will come into force next year, a shorter consultation with a doctor or a psychologist will suffice, along with approval from The National Board of Health and Welfare.

The new law will also decouple the process of legal gender change from medical procedures like sex reassignment surgery, which will still require a lengthier evaluation.

Backers of the bill say it's a modernisation of the existing law that will put Sweden closer to Nordic neighbours and many other European countries, which already have systems for people to determine their legal gender.

"This is not a revolution we are doing today, it is a reform," said Johan Hultberg of the Moderates during a debate. "It is not reasonable that there should be the same requirements for changing legal gender as for making an irreversible gender-confirming surgery." However, the bill is unpopular, especially with voters to the right.

According to a recent poll commissioned by TV4, 59% of Swedes say it is a bad or very bad proposal, while 22% think it is a good one.

It has also split the government. To pass the bill, the centre-right Moderates and the Liberals worked with the centre-left opposition, circumventing the government coalition partner the Christian Democrats and government backers the Sweden Democrats.

Critics argue that more evaluation is needed and that the law change could make some women feel uncomfortable if they have to share changing rooms with those who have transitioned.

"We believe that this is a reprehensible proposal, which risks having unforeseen and serious consequences," said Carita Boulwen of the far-right Sweden Democrats. "Not just for the individual, but for society as a whole."