Prime Minister Justin Trudeau still faces resistance from the Conservative opposition and some provincial leaders as the federal budget approaches on April 16.

In a letter to the Prime Minister issued on Sunday, Conservative leader Pierre Poilievre once again expressed his criticism of the government's handling of a range of issues—from housing to the carbon tax to the economy in general.

He said the federal government would need to meet three demands to gain Conservative support: repeal the carbon tax; adopt the Conservatives' housing proposal; and end government spending without matching cuts.

Poilievre said in the letter: "Conservatives of sound mind will only support the budget if these three conditions are met." "It is time to turn the harm your government has caused into the hope Canadians so desperately need."

Trudeau has strongly defended the carbon tax in recent weeks and is unlikely to agree to Poilievre's other proposals.

The confidence and supply agreement between the New Democratic Party and the Liberals means that the governing Liberals are likely to have enough support to pass budget legislation without backing from other opposition parties.

Trudeau and federal ministers have toured the country in recent weeks to issue a series of pre-budget announcements. Many of these announcements focused on housing, but Trudeau also pointed to the government's intention to launch a national school food program and invest in the artificial intelligence sector.

These announcements have often taken on a campaign tone, as Trudeau frequently seizes the opportunity to launch attacks on Poilievre.

Trudeau said on Sunday in Montreal following his announcement on AI spending: "Pierre Poilievre continues to promote austerity and cuts as the way forward for Canada and Canadians. He is wrong."

He also defended his handling of the economy and the deficit, which Poilievre had criticized.

Trudeau said: "The job of the opposition leader is to criticize the government, which we understand. But this is not about spreading fear."

Some upcoming budget measures have also faced regional opposition, which could pose a challenge.

The national school food program and various housing announcements will require provincial approval to be effective.

The carbon tax continues to fuel premiers

In an interview aired Sunday on Rosemary Barton Live, Progressive Conservative New Brunswick Premier Blaine Higgs said he would consider cooperating on the government's new housing infrastructure fund, but only if they could have an open discussion about the matter.

He told CBC's chief political correspondent Rosemary Barton: "I want to work with the federal government, and I don't like the idea of the federal government bypassing the provincial government to get things done in a way that [Trudeau] feels is more productive."

In a separate interview, Alberta government minister Jason Nixon, whose portfolio includes housing, said the federal government does not invest evenly across provinces, has not allocated sufficient resources to Indigenous communities, and objected to the federal government's approach to handling cross-jurisdictional issues.

He added: "They have continued to come into our province, bypassing the provincial government, and trying to work directly with municipalities or other service providers. That is not appropriate."

"This province will not be bribed with federal dollars to allow the federal government to continue entering our province and entering our jurisdiction."

Premiers continue to pressure the federal government over the carbon tax, which has been a point of contention for months between the Liberals and many provincial leaders.

Liberal Newfoundland and Labrador Premier Andrew Furey sent a letter to Trudeau last week requesting an emergency federal-provincial meeting on this issue.

Higgs told Barton that premiers have not received a response to this request. He said the federal government should allow provinces flexibility in their approach to reducing emissions and adopt a global perspective—allowing exports like national gas to help lower emissions in other countries.

Trudeau challenged premiers calling for an end to the carbon tax to instead come up with their local plans for reducing emissions.

Trudeau said on Sunday: "If premiers want to propose another way—individually or collectively—to fight climate change and support affordability for Canadians, I am all ears."