Updated at 8.15pm - Added PL statement

Opposition Leader Adrian Delia challenged Labour deputy leader Chris Cardona on Wednesday to explain what lay behind the allegations that he had met one of Daphne Caruana Galizia's alleged killers.

He was speaking in Parliament after the Wednesday evening sitting was adjourned by Deputy Speaker Claudette Buttigieg, following Dr Delia's invocation of standing orders seeking an urgent public debate on the allegations. 

Times of Malta revealed on Tuesday that patrons of a bar in Siġġiewi have alleged that Dr Cardona was seen chatting with one of the three men charged with Ms Caruana Galizia's murder, both before and after the assassination. 

Dr Cardona said he could not recall any such encounter. 

“Six months ago, the Prime Minister said that the government would spend all necessary to find out who was behind the murder. Who was behind the murder? People have a right to know,” Dr Delia said on Wednesday.

“There are procedures already underway about who carried out the crime but not who commissioned it and that it what the world wants to know.”

DAPHNE PROJECT: $1.6m wired to Mizzi and Schembri's 'target client'

“And did police commissioner know about this? Did he investigate?” he asked, pointing out that the police had a strange sense of priorities, having on Wednesday chased his predecessor, PN MP Simon Busuttil, about posters in the boot of his car.

Dr Delia said that the eyes of the world were on Malta and that failure to act would have grave, long-term repercussions on the economy.

"The government cannot keep fooling people into thinking it's business as usual," he said as he made reference to further revelations published in Times of Malta concerning minister Konrad Mizzi and the Prime Minister's chief of staff Keith Schembri. 

MP Chris Fearne challenged Dr Delia to say whether he had ever been to the bar in question, which was in his constituency, or whether anyone seated on Parliament's backbenches had a relationship of any type with the accused.

He also called on Dr Delia to explain claims made by the late Ms Caruana Galizia that he had earned thousands every month from an address in Soho linked to prostitution - a statement which was immediately objected to by Dr Delia.

The Opposition leader said that he had visited the bar many times, either to have a drink with his wife or to make a purchase, but he had never met any criminals there.

MP Glenn Bedingfield challenged Nationalist MP Mario de Marco to state whether he had ever represented Mr Degiorgio, one of Ms Caruana Galizia's alleged killers, and to say what the links were with his family.

Dr de Marco acknowledged ties, saying that there were civil cases in court relating to apartments in St Paul's Bay and adding that there was nothing sinister about his involvement with this case, which stretched back to 2013.

His fellow PN MP Jason Azzopardi later said that Dr Cardona was himself the attorney of one of the accused in a case which was still awaiting jury proceedings, but that no attorney was doing anything illegal by representing any client in any case.

Mr Bedingfield rebutted with another claim that one of the Degiorgios had been working as a driver for some Nationalists, causing another uproar in a session which was marked by interruptions and name-calling.

Dr de Marco's statement was immediately seized upon by the Prime Minister's chief of communications Kurt Farrugia, who said on Twitter that the relationship between Dr de Marco and Mr Degiorgio was "worth investigating", given that "Caruana Galizia was a harsh critic of the de Marco family."

In a statement issued later in the evening, the Labour Party reiterated that position and called on Dr Delia to say where he stood on the matter. 

"It is also time for the Leader of the Opposition to start providing concrete answers to Daphne Cariana Galizia’s allegations on prostitution, money laundering and drugs," the PL said. 

"The only honourable way for him is to subject himself to investigations by an independent magistrate."