A move to eliminate “sexual orientation” from a Japanese city’s groundbreaking antidiscrimination ordinance would be a damaging blow to the cause of full equality, gay activists at Human Rights Watch (HRW) said in a letter to the city’s mayor this week.

The city assembly of Miyakonojo has begun debating the proposed changes week but Scott Long, director of HRW’s lesbian, gay, bisexual and transgender rights programme warned that equality should never be taken away.

He wrote in the letter to mayor Nagamine Makoto, “Rights should never be subject to repeal, a city that became a model of progress by affirming equal rights must not break its promises now.”

In 2003 the southern Japanese city of Miyakonojo, located in Miyazaki prefecture, became one of the first cities in the country to include “sexual orientation” in its gender-equality ordinance.

The national “Basic Law for a Gender-Equal Society,” passed by Japan’s Diet in 1999, required local governments to develop laws and policies promoting equality between men and women. While the national law did not mention sexual orientation, Miyakonojo ‘s ordinance stated: “In the gender-equal society, for all people irrespective of gender and sexual orientation, human rights should be fully respected.”

Early this year, Miyakonojo was consolidated with three other towns, and officials agreed that all ordinances passed before that date would undergo review.

After a closed process, with no invitation for citizens or LGBT groups to present their views to the city assembly in hearings, a revision was proposed in which references to “gender” and “sexual orientation” were both dropped from key articles of the ordinance.

The city’s website states that the revision is meant “to simplify the contents.”

“The city of Miyakonojo led by example,” said Long. “It cannot retreat in the face of prejudice now.”

There are no Japanese laws against gay sexual activity but there are only limited laws against discrimination based on sexual orientation in certain parts of the country. Marriage has been strictly defined as a male and female union.