Culture Minister Owen Bonnici has taken over from Chris Fearne as leader of the house of representatives as the former deputy prime minister's responsibilities continue to be reassigned amid the fallout from the Vitals inquiry.
The announcement, published in the government gazette, means Bonnici will be responsible for setting parliament's agenda.
It is a role that is usually assigned to a deputy prime minister but Robert Abela has so far held off on officially designating a deputy and there is no constitutional requirement for him to do so.
Sources said Bonnici will become acting prime minister when Abela is absent from Malta or otherwise unable to perform the functions of his office.
As the most senior member of cabinet, Bonnici had assumed the role several times when either the prime minister or Fearne had been indisposed.
Fearne resigned from cabinet earlier this month as he faces fraud charges against him related to the deal to privatise three state hospitals.
The office of the prime minister took over his EU funds, reforms and social dialogue portfolio.
Fearne also withdrew as Malta's nominee to the next EU Commission and while Environment Minister Miriam Dalli is seen as a possible replacement, no announcement has been made.