Thai Prime Minister Prayut Chan-ocha has joined a new party as he looks for ways to extend his eight-year rule despite term limits, signaling shifting alliances and a ramp up in political jockeying ahead of elections slated for May.

On Monday, Prayut became a member of the newly formed Ruamthai Sarngchart party, which has pledged to name the former army chief as its candidate for prime minister. The move completes his split with the military-backed Palang Pracharath party that backed his bid for the top job four years ago.

"There’s work to be finished and that’s why I must step up to do this,” Prayut said after signing up to become a member of Ruamthai, also known as the United Thai Nation party. "I’m here not because I want to stay but because Thailand has to carry on.”