Malaysian opposition leader Anwar Ibrahim will make an "important announcement" on Tuesday after a meeting with the king in which he aims to prove he has the parliamentary support needed to oust Prime Minister Muhyiddin Yassin.
Anwar will hold a news conference at 0600 GMT "regarding an important announcement post-audience with His Majesty", his party communications director, Fahmi Fadzil, said in a statement.
Anwar added a fresh twist to the Southeast Asian nation's political drama last month when he declared that he had secured a "formidable" majority from federal lawmakers to form a new government.
The power struggle comes as Malaysia, already grappling with an economy battered by the novel coronavirus, faces a renewed surge in infections.
Anwar was seen entering the palace grounds at about 10.30 a.m. (0230 GMT) and left about an hour later, the Bernama state news agency reported.
Should Anwar succeed in securing the post, it would be the culmination of a 22-year long quest, which included nearly 10 years in jail on charges he denied. It would also mean Malaysia would have its third prime minister this year.
But scepticism over Anwar's challenge remains as no major party has offered a clear declaration of support. One party, which is a member of the ruling coalition, has said some of its lawmakers supported Anwar.
"Should the meeting fail to translate into an actionable outcome, his credibility will be affected and this may push the opposition bloc to find another PM candidate," said Shazwan Mustafa Kamal, senior associate at political consultancy Vriens & Partners.
Muhyiddin, whose seven-month-old administration has survived on a razor-thin parliamentary majority, had earlier dismissed Anwar's claims as a "mere allegation" and told him to prove his majority through a constitutional process.
Leaders in Muhyiddin's Perikatan Nasional coalition issued a statement on Monday declaring full support for Muhyiddin.
King Al-Sultan Abdullah plays a largely ceremonial role but he can appoint a prime minister who in his view is likely to command a majority, so Anwar will need to convince him he has such backing.
The king could also dissolve parliament and trigger elections on the prime minister's advice.
It was not clear if an outcome would be known on Tuesday.