Updated 8.50 pm 

Robert Abela has alleged that the Nationalist Party is setting a "trap" for Labour supporters who will gather in support of Joseph Muscat next week. 

Abela said the Opposition wants to "stoke tensions" on the day that a "solidarity meeting" for Muscat outside the Valletta law courts takes place. 

In an immediate video response, Opposition leader Bernard Grech slammed Abela for irresponsibly stoking tensions and told him to go to the police with the information, if the claims are true. 

The demonstration is set for Tuesday, around the same time former Prime Minister Muscat is due to be arraigned on corruption charges.

Various Labour ministers stopped short of endorsing the rally when asked for their views about it on Tuesday. Instead, they urged attendees to remain calm and to make themselves heard by voting Labour on June 8.

Speaking outside Castille on Tuesday afternoon, Prime Minister Abela spoke more directly about the demonstration.  

"I am informed that on May 28, the Nationalist Party is planning a trap that is not nice at all. My appeal to the people is to keep calm and not to be provoked," he said. 

Abela said he was confident that the rally would remain peaceful, saying "just like [Muscat] never fell for the traps the PN tried on him, he will not allow anyone to fall for this one". 

Abela did not provide specifics about his allegations when asked to do so. 

"The last hope the PN thinks it has to get back here [Castille] is to stoke tensions. It's a very ugly trap," Abela said. 

"I understand why the Opposition has been speaking about the 1980s. They are again using tactics of that era," he said. 

Abela said the only strategy for the ongoing electoral campaign is the Vitals hospitals deal inquiry and its aftershocks. 

The prime minister was repeatedly asked if he endorsed the solidarity demonstration, but did not give a yes or no answer. 

Abela was speaking hours after a Castille cabinet session. 

During a political activity later on Tuesday evening, Abela once again appealed to his supporters to remain calm, urging them to "take the high road" in the face of the Opposition's "provocations". 

In a video message posted to Facebook shortly after Abela's comments were publicised, Opposition leader Bernard Grech slammed Abela, calling his action "dangerous" and urging him to go to the police if his information is to be believed. 

"It is evident these are comments of a desperate person who has not only lost control of the Labour Party and the government but is a Prime Minister who instead of doing everything he can to make sure our institutions work with serenity, is not only attacking them, but is making up stories about the PN," Grech said. 

"Robert Abela, you must stop this dangerous attitude immediately. Your speech is intended to rile people up, to do damage and create trouble. So that’s why I am warning you to put a stop to this behaviour."

Grech appealed for caution and urged people not to give in to the Prime Minister's provocations. 

Ministers appeal for calm

Earlier ministers funnelling out of cabinet were asked if they endorsed the "solidarity meeting". 

Like Abela later, the five ministers made similar appeals for calm and caution against provocation. 

Lands Minister Stefan Zrinzo Azzopardi appealed for calm, adding "what's important is that people vote on June 8". 

Culture Minister Owen Bonnici and Public Cleansing junior minister Glenn Bedingfield both made identical comments.

Equally, Finance Minister Clyde Caruana said: "In this moment, the important thing is to remain calm; we live in a civilised country where people have matured - what's important is to keep calm".

Home Affairs Minister Byron Camilleri said it was not his job to endorse or not endorse the meeting, but warned against falling for "provocation". 

"We know the PN's tactic in this campaign: to provoke. They did it in parliament and in other instances towards us," he said 

Muscat is set to be arraigned by summons (not under arrest) next Tuesday. 

He faces criminal charges of money laundering, bribery, trading in influence and a long list of other charges, including setting up a criminal association, in connection with a deal to privatise three state hospitals. 

Muscat has said he is innocent of all charges.

"I am going to relish destroying each and every one of these charges and proving how they are built on fantasy and lies," he said earlier this month.

Next week's "solidarity meeting" is being organised by Muscat ally Emanuel Cuschieri and relayed by his lawyer and friend Charlon Gouder and another close Muscat friend, former Labour general secretary Jason Micallef.