Chinese hotel bookings to Thailand for Spring Festival have tumbled as a crackdown on cheap package tours hits visitor numbers from its biggest source of vacationers.

Tourism is increasingly important for Thailand given that its economic growth lags behind other Southeast Asian economies. Between 2012 and 2016, the number of Chinese visitors tripled to nearly a third of all Thailand's tourists by numbers and revenue.

But a crackdown on "zero dollar" all-inclusive package tours in September sent that into reverse with little sign of recovery ahead of the Spring Festival holiday season, Jan 27 to Feb 2.

D Land Holiday Co, which caters to Chinese tourists, has only 300 bookings for the holiday compared with 800 last year, its owner said.

"It's the crackdown," Ruengdet Amorndetphakdee said.

Other companies, such as Central Plaza Hotel PCL, said Chinese bookings had fallen. Tristar Floating Restaurant Co has six cruise ships for Chinese visitors, but is operating only one.

Thailand's tourism authority expects a 7.7 percent drop in Chinese tourists during the Spring Festival holiday, though it expects it to be at least partially offset by a 3.9 percent rise in tourists from elsewhere.

Zero dollar tourists pay everything upfront.

Operators cut any cost they can, while tourists are sometimes cajoled into buying overpriced souvenirs so the company earns a commission. Those are the practices Thailand wants to stop.

But the government's insistence on a minimum 1,000 baht ($28) per night charge for package tourists made Thailand uncompetitive for many Chinese visitors, tour operators say.

"We weren't prepared for this," said Chanapan Kaewklachaiyawuth, secretary-general of Thai-Chinese Tourism Alliance Association.

Chinese tourist numbers fell by 30 percent in November from the year before to the lowest monthly total in more than two years.