Prime Minister Stephen Harper offered his first public comments about Quebec's proposed secular charter of values Monday, saying the Parti Québécois government's attempt to ban the wearing of religious symbols by public servants isn't "going anywhere" as it stands.

Harper was asked about Quebec's controversial charter of values following an event in B.C. to announce new measures to track child sex predators who leave the country for travel abroad.

"I don't see the charter in its current form going anywhere. I think the common sense of Quebecers will force this to a reasonable conclusion," Harper told reporters.

It was the first time Harper has commented on the proposed charter of values since the PQ unveiled details last week.

Harper said if the Quebec national assembly was to adopt a charter of values that was found to violate the rights of Canadians, Ottawa would take "whatever action is necessary."

NDP Leader Tom Mulcair also held a press conference on Parliament Hill Monday, to draw attention to the fact that MPs would be back at work if Harper had not prorogued the House until Oct. 16.

He was asked about reports published in the French newspaper La Presse that the Quebec government ignored a legal opinion from lawyers and experts in its Justice Department saying the proposed charter of values was "unconstitutional."

Mulcair said he would have been surprised if the legal opinion had said otherwise because the proposed plan is "patently illegal."

The NDP leader also indicated the party was prepared to cover the costs of any legal challenge using Montreal constitutional lawyer Julius Grey to lead the charge.

Opposition holds 'virtual question period'

Mulcair told reporters that Harper's decision to delay MPs' return from summer break for another month shows "his disdain" for Parliament.

NDP Leader Tom Mulcair, centre, says Prime Minister Stephen Harper's use of prorogation shows his "disdain" for Parliament, during a press conference with MPs Nathan Cullen, left, and Nycole Turmel Monday on Parliament Hill in Ottawa. (Adrian Wyld/Canadian Press)

"I believe we would have been able to accomplish a great deal in the public interest," Mulcair said.

The NDP took to Twitter Monday to hold a "virtual question period" as a way to hold the government to account during prorogation.

Mulcair and his party critics tweeted the questions they would have asked the government if the House of Commons were sitting this week using hashtag #QPQ.

Mulcair was first up with a series of questions for Harper about the Senate expenses scandal beginning with this question: "On June 5th, @pmharper told the House no one in his office other than Nigel Wright knew about the $90K. Does the PM stand by this?"

​There was no response from Harper or the Prime Minister's Office on Twitter but in an email to CBC News, a spokesperson for Harper said the Conservative caucus "will return following an active summer working hard in their constituencies with a renewed focus on improving the economy and protecting the security of Canadian families."

NDP industry critic Chris Charlton managed to draw the ire of ​Industry Minister James Moore after she asked him why the Conservatives are "afraid to study telecom and consult with Canadians?"

Moore replied that he was getting in the car and couldn't answer right away, dismissing the NDP strategy as "juvenile tactics."

Minutes later, Moore answered back "typical NDP – when they have *nothing* of substance to offer, they suggest more process to appear engaged & insightful."

NDP critics also tried to engage Transport Minister Lisa Raitt on railway safety regulations and Treasury Board president Tony Clement on the government's intention to appeal a labour board ruling that found the federal government negotiated in bad faith with striking diplomats.

Over the weekend, it was former diplomat and Immigration Minister Chris Alexander who issued a reply to the labour board ruling, and not Treasury Board.

NDP House Leader Nathan Cullen said the New Democrats will hold a virtual question period every day until Parliament resumes to ask questions on behalf of Canadians, "questions this government seeks to avoid."

Cullen told reporters gathered in the Foyer of the House of Commons in Ottawa earlier on Monday that the Official Opposition planned to ask "questions of accountability, questions on our economy, questions on foreign affairs,"

The NDP also gave notice it will table a motion to end the Conservative muzzling of federal scientists.

"Harper's shutting down of scientists, of firing them, or of muzzling the ones that he hasn't fired is for us an approach that goes completely against the nature of a Parliament where things have to be debated openly," Mulcair told reporters.

Canadian scientists and their supporters planned demonstrations across the country on Monday, calling on the federal government to stop cutting scientific research and muzzling its scientists.

On Monday, Liberals convened a roundtable on the future of the wireless industry with MPs and stakeholders.

Liberal Leader Justin Trudeau has said Liberal MPs will return to work as scheduled. He will hold a news conference in Ottawa on Tuesday.