Ontario Premier Doug Ford is accusing Prime Minister Justin Trudeau of being "selective" when it comes to condemning provinces' use of the notwithstanding clause, and is warning against him engaging in constitutional talks with Canada's premiers.

"It's very disappointing. The prime minister is being selective within certain provinces, about his concerns of overturning the notwithstanding clause," Ford told reporters during a press conference on Monday morning.

Trudeau has been highly critical of Ford's recent decision to invoke the notwithstanding clause in Bill 28—an Ontario law that passed last week to override sections in the Charter of Rights and Freedoms to legislate a contract with 55,000 education workers and to make it illegal for them to strike— calling it "wrong and inappropriate."

"The proactive use of the notwithstanding clause is actually an attack on people’s fundamental rights and, in this case, is an attack on one of the most basic rights available—that of collective bargaining," Trudeau said last week, indicating the federal government was looking at its legal options. However, on Monday, Ford signalled he’s willing to rescind the law if workers return to class.

In defence of his government's move, Ford said Monday that the clause is a "constitutional tool for provincial governments to use."

"It's well within our government's right to use this tool," said the premier.

Ontario is not the only province to invoke the contentious override clause of the Charter of Rights and Freedoms in recent years. While Ford didn't point to a specific example of how Trudeau has been "selective" in his condemnation, Quebec has used the clause twice pertaining to language and religious symbols laws during Trudeau's tenure. 

While the prime minister has voiced concerns about Quebec’s use of the notwithstanding clause, Trudeau has also faced calls from both his federal opponents and members of his own caucus to be more vocal and challenge Quebec Premier Francois Legault’s use in the case of Bill 21.

"If the prime minister wants to sit down and have a constitutional conversation with all the premiers, I can assure you all the premiers will be there to talk about the constitutional changes, if he wants to go down that road," Ford said. "I'd highly recommend not to."

Asked on Monday to respond to Ford’s suggestion, Trudeau said there are plenty of priorities Canadians have for their federal and provincial leaders, and engaging in constitutional conversations are far from top of mind.

“This government will never back down from standing up for people's rights and freedoms,” Trudeau said. “And if premiers across the country want to avoid the kind of disruption that we've seen in Ontario over these past few days, the answer is simple. Just don't use the notwithstanding clause, proactively.”

With files from CTV News Toronto