The government was accused on Sunday of hindering discussion on TVM as programme host Mark Laurence Zammit resigned after complaining of interference by the state broadcaster.
He is joining Times of Malta instead.
"First they got rid of Daphne. Then they removed Xarabank. Now they have shut up L-Erbgħa fost il-Ġimgħa" shadow minister Joe Ellis said in a reference to the programme presented by Zammit.
He noted that TVM was also moving news and political discussion from TVM to TVM-2 in what was clearly a new propaganda tool for the government.
Ellis observed that the prime minister was refusing to give interviews to the independent media and was only interested in strengthening the Labour media with adverts paid by taxpayers.
"PBS is trying to make people believe that Mark Laurence Zammit did not follow the station's rules, but the truth is that it is PBS which is not following the rules, such as by not following directives of the Broadcasting Authority, Ellis said.
Earlier, Rule of law NGO Repubblika said this was a very serious matter, especially as the interference had been made by the national broadcaster, which is funded by taxpayers and is supposed to be politically neutral and not a government tool.
The NGO said it had no confidence in minister Carmelo Abela, who is responsible for PBS. He had not even been able to shoulder responsibility after being found guilty of breaching ministerial ethics by the Standards Commissioner and he therefore lacked the moral authority to ensure that the broadcaster observed its duties.
The prime minister therefore, had a duty to investigate what had happened, discipline whoever was involved, and inform the people of his actions.