Updated Friday 11.30am with PN reaction

Tony Zarb's attack on the head of the Pana committee is reflective of the "divisive" politics of Joseph Muscat, according to the Nationalist Party.

The PN was reacting after the former General Workers' Union boss and Labour activist appealed to the government to declare Werner Langen a persona non grata and to protest with European institutions following his "behaviour" during a hearing on Wednesday.

During a scathing European Parliament debate about the rule of law in Malta, Mr Langen vowed that he would continue to pursue Dr Muscat to ensure he did not get off “scot-free”.

Read: Get your facts right, Muscat tells MEPs

The PN's MEPs have also been subjected to a barrage of insults and criticism on social media following their intervention in Wednesday's debate.

In a statement this morning, the PN said Mr Zarb's comments reflect the "falseness" of the Prime Minister who speaks about national unity yet instigates those close to him to spread hate against PN exponents.

"The PN challenges the Prime Minister to cancel the vindictive transfers that have been carried out since the election if he really believes in the national unity he preaches about. If he ignores the hundreds of people falling victims to such transfers it would confirm that he's nothing but fake."

Mr Zarb said if it were up to him no Maltese government official would appear before the Pana Committee as long as this was headed by Mr Langen, who he said had already reached his conclusions so he could not be fair in his decisions.

One of a number of Facebook posts from Tony Zarb.

"Mr Langen was very close to the Nationalist Party and enjoyed rubbing up against David Casa's backside and front and Roberta Metsola's front", the former union boss said. 

Mr Zarb appealed to the Maltese to be careful and not allow anyone to vilify their country. He said that he would never forgive anyone who did, whether he was Maltese or a foreigner.

Many Labour supporters also resorted to Mr Langen's Facebook wall to hurl insults at him and to stop interfering in Malta's affairs. 

Others suggested that Mr Casa and Dr Metsola should be pelted with eggs when they returned to Malta.