Romania's ruling Social Democrats (PSD) lost their small parliamentary majority on Monday after a junior ally quit government over policy, leaving them vulnerable to a confidence vote.
Liberal party ALDE withdrew from the alliance two days after leader Calin Popescu Tariceanu lost a bid to become the sole pro-government candidate in a presidential election scheduled for November. The PSD instead picked its leader, Prime Minister Viorica Dancila, to challenge incumbent Klaus Iohannis.
ALDE's move, a year before a parliamentary election, would normally raise the prospect of an early ballot. But a fragmented opposition may prefer to wait the full term out, analysts say.
"I don't see many (other parties) rushing to take over now," said political commentator Cristian Patrasconiu. "(Waiting for the election) is the most rational political stance."
Himself a former prime minister, Tariceanu said the PSD had performed poorly in government and failed to take the necessary steps to restructure the cabinet. ALDE's decision to pull out however not been easy, he added.
EU and U.S. authorities have strongly criticised the governing alliance for an overhaul of Romania's judiciary that they say threatens the rule of law, and for watering down anti-graft legislation.
Dancila said the PSD would continue to govern. "The important thing is to not disappoint our voters who trusted us in 2016 (national) elections," she said on her Facebook page.
Monday's divorce, which leaves the PSD 25 seats short of a parliamentary majority, could hamper policymaking, however, forcing her to negotiate legislation on a bill-by-bill basis.
Dancila has 45 days to ask parliament for a vote of confidence and, in the meantime, needs to find new appointees for three ALDE-held ministerial posts and will seek to ally with other political groupings, probably including the ethnic Hungarian UDMR.
Voters turned on the government in European parliament elections in May, with the PSD's support almost halving while ALDE was unable to reach the threshold to enter the assembly.