Thailand’s pro-democracy parties faced built-in obstacles to forming a government even before a historic win in Sunday’s election. Now that resistance is starting to take shape, making investors wary of a protracted political uncertainty.

Pita Limjaroenrat, whose Move Forward party won the most seats in Sunday’s election, said on Thursday that the coalition has expanded to eight parties with 313 members. While that’s a clear majority among elected lawmakers in the 500-member House of Representatives, it’s short of the 376 that’s needed for the bloc to form a government without needing votes from the 250-member, military-appointed Senate, which also gets to decide the prime minister in a joint sitting.

Signs of a tough fight ahead emerged after Bhumjaithai, a party that came third in the election with 70 seats, said it won’t back Pita to become prime minister because of his quest to change Article 112, a law that mandates as many as 15 years in jail for insulting top royals, including King Maha Vajiralongkorn. The Senate, dominated by royalists, is likely to follow suit.