HALIFAX - Liberal Leader Stephane Dion is promising $900 million over four years to create a new plan for catastrophic drug coverage.

In what Dion called "one of the most fundamental policies a government can provide to its citizens," the plan would cover drug costs for people living with serious illnesses such as cancer, diabetes, and arthritis.

Society has an obligation to help people with debilitating, chronic illnesses meet high prescription-drug costs that create prohibitive financial burdens on families, Dion said.

He said the proposed Liberal plan would ensure all Canadians have access to badly needed drugs no matter where they live.

"In the Canada we want, Canadians battling a serious illness should not be forced to sell their house to buy the prescription medicines they need -- not in our Canada. Never."

Dion said a Liberal government would work with its provincial and territorial counterparts to determine a minimum standard for federal coverage of catastrophic drug costs.

The Liberals would also compensate provinces that are already providing that level of coverage, he said.

The Liberal leader spoke at Dalhousie University's medical school, which is where NDP Leader Jack Layton was Monday to unveil a $1-billion plan to dramatically increase the number of nursing and medical students in Canada.

The level of prescription drug coverage varies considerably from province to province, Dion said.

But he noted the problem of meeting catastrophic drug costs is particularly critical in Atlantic Canada, where 24 per cent of the populace, or 600,000 people, have no drug plan.

"Far too many people who are not poor enough to be on social assistance and certainly not wealthy enough by any definition to afford the cost of these drugs are left to fend for themselves," he said.

"When the drug costs of an illness become too much for a family to manage, the federal government should be there to help."