Director-general Siripol Yodmuangcharoen said manufacturers could not meet demand.

The department has cooperated with seven manufacturers who are producing 5,000 shirts per day, he said.

Orders in Bangkok total more than 150,000, while 90,000 of the T-shirts have been requested upcountry.

Siripol said the department would consider increasing production in August if demand remained high.

He said 200,000 to 500,000 T-shirts would come out next month and would be distributed to 108 Shop, Big C, Macro and 7-Eleven.

Demand for the T-shirts surged in the run-up to the celebrations of the 60th anniversary of HM the King's accession to the throne on June 8.

The T-shirts were the best sellers at booths selling souvenirs of royal projects in the Grand Exhibition at Muang Thong Thani.

Many people had to queue for hours to make a purchase, and most bought several at a time, vendors said.

Demand shows no sign of waning, however, as many people have decided to wear the T-shirts every Monday throughout the year to express their loyalty to the King.

State authorities, state enterprises and several private companies have also asked their employees to wear the T-shirts every Monday or Friday.

Petchanet Pratruangkrai

The Nation