The CNRP has written a letter to the National Assembly calling for Interior Minister Sar Kheng to expedite the processing of passports for up to 1,000 illegal Cambodian migrant workers who have been languishing in Thailand for the past 18 months.

According to the letter sent last week, each worker paid 1,400 baht (about $40) for a passport to a government delegation in January of last year, but their documents had not yet been delivered.

CNRP lawmaker Ky Vandara said the lack of documentation was problematic, because simple resident cards restricted their freedom of movement.

“I regret they did not get their passports even though they paid already in 2015,” he said.

Spokesmen for the Ministry of Labour and the Ministry of Foreign Affairs declined to comment, saying it was a matter for the Interior Ministry, which could not be reached yesterday.

Moeun Tola, executive director of labour rights group Central, said the lagging bureaucracy was a key reason so many Cambodian people in Thailand remained undocumented and vulnerable to exploitation.

Additional reporting by Erin Handley