Prime Minister Prayut Chan-o-cha has ordered the Transport Ministry to proceed with a plan to tackle the soaring prices of air tickets.

The Civil Aviation Authority of Thailand (CAAT) has developed its five-point plan to deal with the issue that has frustrated passengers, affecting the tourism industry.

Prayut has told the CAAT to keep tabs on domestic airfares and urged people to plan their trips in advance for more affordable air tickets.

The CAAT has proposed five measures, including increasing ground-handling capacity, relaxing rules to create flexibility for airlines, and considering a subsidy programme.

Incentives should be introduced to encourage airlines to return their flight slots as early as possible if they cannot operate the flights so that the slots can be reallocated, officials said.

Airlines are operating with a limited number of aircraft, so rules could be eased to enable them to buy more aircraft to solve the seat capacity problem, the CAAT said.

The CAAT suggests airlines should be given more flexibility regarding maintenance work carried out in other countries.

As a long-term measure, laws should be improved to promote investment in maintenance centres to serve the country's growing airline business.

Air tickets on certain routes are expensive due to low market demand or the service being provided by a single operator.