Ministers and Parliamentary Secretaries were seen walking into Castille on Thursday night for an hastily-called Cabinet meeting.
The meeting is taking place at the end of another action-packed day brought about by the Daphne Caruana Galizia murder probe.
The agenda of the meeting are not known though Yorgen Fenech's request for a presidential pardon to tell all and the political crisis are expected to be discussed.
Joseph Muscat has faced mounting pressure to resign himself following the arrests of his former chief of staff Keith Schembri and the resignation of Tourism Minister Konrad Mizzi.
"The situation is serious," deputy prime minister Chris Fearne told reporters on the way in, but refused to give any details.
Going in later, Minister Michael Farrugia said Cabinet was convened whenever it was necessary. "We will inform the media of the proceedings once the meeting is over."
According to witnesses, the Police Commissioner and the Attorney General were also seen entering Castille through the back door.