Priewpong Charoenviriyapab sent a copy of the petition through the Office of His Majesty's Principal Private Secretary last Thursday.

He said the CDA candidate selection last Monday was confusing, and not free and fair. He called for a suspension of the process until the King gives a ruling.

Royal endorsement for selected candidates is expected to be given by the end of this month.

Many NPA members who arrived early last Monday received ballot cards almost two hours before the designated selection time.

They were also allowed to move around with the ballot papers, talk freely with others and even reveal the content of their papers - a move some NPA members said compromised the selection process and enabled bloc-voting to occur unchecked.