"About half of candidates nominated by the People Power Party are deemed inappropriate for the job," he said.
He declined to comment on the qualifications of Wan Yoobamrung, son of Interior Minister Chalerm.
Samak also distanced the Cabinet from the planned cancellation of the 30 per cent capital control by designating the Finance Ministry and the Bank of Thailand to review the issue.
The government would not interfere in the matter, he said.
In regard to the compulsory licensing of cancer drugs, he said he instructed three ministries, Public Health, Commerce and Foreign Affairs, to conduct a review before reporting back to the Cabinet.