The parliamentary group of the Nationalist Party on Wednesday backed concerns voiced by the Caruana Galizia family about the composition of the board of inquiry to investigate whether the government could have acted to prevent Daphne Caruana Galizia's murder.
The journalist was killed by a car bomb outside her home on October 16, 2017.
The government announced it would hold a public inquiry just days before a deadline set by the parliamentary assembly of the Council of Europe expired.
It said the board would be headed by retired judge Michael Mallia, with lawyer Ian Refalo and retired forensics expert Anthony Abela Medici as its members.
The family had immediately voiced concerns about the nominees, particularly Prof. Refalo and Dr Abela Medici, and requested a meeting with the Prime Minister.
Joseph Muscat had said he is prepared to meet the family once he returned from New York, where he is attending the annual United Nations General Assembly.
PN concerns
The PN parliamentary group said it discussed the appointment of the inquiry on Wednesday, having itself insisted for months that it should be set up.
"The PN insists that the outcome of the inquiry should leave no doubts, and therefore, the composition of the board to conduct it should have the unanimous backing of all concerned, particularly the family of Daphne Caruana Galizia," the PN said.
The party said it agreed with the appointment of Judge Mallia but "independently of their professional competence and integrity," it could not agree with the appointment of Prof. Refalo and Dr Abela Medici as board members, for various reasons.
The PN said that the position of the Caruana Galizia family should be upheld and no persons who did not enjoy its respect should be appointed.
Prof. Refalo's appointment has been criticised because he is the legal adviser of the Financial Intelligence Analysis Unit and of former Allied Newspapers managing director Adrian Hillman, both of whom were the subject of blogs by Caruana Galizia.
Dr Abela Medici has been viewed as unsuited for the task, serving in the role of NGO commissioner without security of tenure.