Thailand's Constitutional Court has ruled that a snap general election in February was invalid, as protests in several parts of the country prevented voting from being completed on the same day.
Prime Minister Yingluck Shinawatra had called the ballot in an attempt to quell often violent protests that were aimed at forcing her to resign.
The court's decision comes two days after the government lifted a state of emergency that had been in place since January as a response to the demonstrations, which were scaled back a couple of weeks ago.
The turmoil in Thailand has hit the baht and shares, and has threatened the tourism industry.
Thailand's SET stock index is -0.1%, while the USD-THB is +0.1% at 32.418 baht.