OTTAWA – The House of Commons resumed sitting on Monday for what's set to be an intense session before Parliament adjourns for the last time before the federal election will be called, and the governing Liberals came out swinging bright and early against Conservative Leader Andrew Scheer.

Environment and Climate Change Minister Catherine McKenna and Finance Minister Bill Morneau began their day criticizing their main opponent for his lack of a climate plan. Meanwhile, Scheer was elsewhere on the Hill doing the same over the government's approach to current trade tensions with China.

At issue specifically for the Liberal ministers: Scheer’s lack of a climate change plan, despite his consistent attacks on the government's imposition of a federal price on carbon -- up to $50 per excess tonne by 2022 -- in provinces who don’t implement their own. The federal Conservatives say the government’s plan is little more than a "tax grab."

It was exactly a year ago, on April 29, 2018 during a sit-down interview on CTV's Question Period, Scheer said that he would be unveiling a climate plan ahead of the 2019 election that will meet the Paris targets without a carbon tax.

Asked whether the plan will meet the UN targets for combating climate change, otherwise known as Paris Agreement, Scheer said "of course."

The Paris agreement sets out an international plan to limit global warming to below two degrees.

"I will unveil a plan that reaches the targets that we have already voted in favour of," Scheer said at the time.

In June 2017, Scheer and his caucus voted in support of the Canadian government implementing the Paris Agreement, stating it was in the best interest of Canadians and recognizing that climate change is a global issue.

Though, eight months later it was on CTV's Question Period again where he walked back that promise. He could not commit that his plan would mean the targets, instead he said his plan would have "meaningful reductions."

This weekend, Scheer said that his party’s yet-to-be-declared approach to combatting climate change would be unveiled before June 21 when Parliament is set to adjourn.

McKenna said — without having seen what Scheer has said is a work in progress — that his plan will "do nothing" on climate change.

She also accused him of developing the plan alongside oil lobbyists and working with a growing cohort of likeminded Conservative premiers who have vowed to fight tooth and nail against the government's price on pollution as a key plank of their plan to reduce Canada's contribution to the global issue of climate change.

Speaking alongside her, Morneau said that the cost of not doing anything to tackle climate change is already being borne by Canadians, citing the record flooding happening across Eastern Canada.

At one point Morneau had a slip of the tongue, nearly calling the Official Opposition Leader "Andrew Ford," as he said that Scheer is not listening to the right people if he's taking any lessons from Ontario PC Premier Doug Ford in developing his climate change plan.

Ford has recently been criticized for cutting a program to plant 50 million trees. The axing of this program came the day after Ford released his 2019 budget that proposed to change Ontarians license plate slogan to "a place to grow."

"Canadians need more… We need to do more on climate change, not less," McKenna said, touting their approach and vowing to stay the course despite the pushback from some.

The federal carbon tax, a key part of a broader plan, has been in place since April 1, in the four provinces that have rejected Ottawa’s call for a climate plan that puts a price on pollution. In these provinces Canadians are directly rebating people as part of their federal tax returns. The payment varies based on the province and by the demographics of a household, but is meant to offset the rising costs of things like gas, while incentivizing people to change their carbon-consumption habits.

Prime Minister Justin Trudeau also pounced on the one-year anniversary of Scheer’s Paris target promise.

"It's a year later, and we’re still waiting," he said, speaking at a Toyota plant where it was just announced that the car manufacturer will start building a line of hybrid SUVs.

"Companies like Toyota, and companies all around the world, and all across Canada understand that the only way to move forward and grow our economy is to also be responsible about the environment," Trudeau said.

In the 2019 federal budget the Liberals announced they are now offering a $5,000 incentive to purchase zero-emission vehicles such as electric or hydrogen-fuelled cars. This will apply to vehicles with a retail value of less than $45,000.

In response to the Liberals' critiques, the Conservatives issued a statement asking "Where is Justin Trudeau's climate plan?" and linked to various articles that have drawn attention to the fact that the Liberals' plan may still not be enough to meet the 2030 targets either.

"He [Trudeau] pretends his carbon tax will achieve Canada's emissions reductions targets under the Paris Accord. But it won't… That's because his carbon tax isn't a plan to lower emissions. It's a plan to raise taxes," the statement reads. "This spring, Conservatives will present Canadians with a real environmental plan that will lower global emissions without making Canadians pay more," the Conservative party statement said.

Asked about his plan, Scheer told reporters on Monday that a "real plan" to tackle emissions is needed, more than a carbon tax.

"Our plan as I mentioned will be unveiled with plenty of time for Canadians to analyze it," Scheer said.