A year after the military took power in Thailand, the regime has postponed elections but the country's former Prime Minister warns the junta may be running on limited time.

"I have always been supportive of a referendum and I think it's important that rules in the form of a constitution should be approved by the people," Abhisit Vejjajiva, former Prime Minister of Thailand, told CNBC. But "the last thing the country wants a year from now is to still be debating about the constitution…it's time that we move on," he said.