Pheu Thai deputy spokesman Anusorn Iamsa-ard said his party members would wear black for a week.
The Pheu Thai members took the action after the Constitutional Court nullified the February 2 election.
Anusorn said if the National Anti-Corruption Commission indicts former Parliament president Somsak Kiartsuranon and senators and former MPs who supported the charter amendment bill on the Senate composition, the Pheu Thai members may have to wear black for longer than a week.
The Nation