New Democrat MPs demanded Monday that the Conservative government compensate thousands of Canadians, mostly new mothers, who were denied sick leave benefits because they were already on parental leave.

The government refused between 2002 and 2013 to pay the 15-week Sickness Benefits to parents who became ill while off work with new babies.

Carissa Kasbohm is one of the mothers who plans to join a class-action lawsuit recently certified by a federal court judge that seeks $450 million in damages for those parents.

The suit is led by Calgary mother Jennifer McCrea, who was denied approximately $6,000 in sick leave money while undergoing a double-mastectomy four years ago, just after the birth of her son.

McCrea’s suit alleges the government took an overly “strict interpretation” of the Employment Insurance Act clause that required those claiming sickness benefits to “be otherwise available for work.”

Kasbohm was diagnosed with a blood disorder while pregnant with her son four years ago when she was denied.

“We pay into the system,” she says. “And here we are fighting for things we shouldn’t be fighting for.”

NDP Deputy Leader David Christopherson says mothers like McCrea and Kasbohm should receive compensation, and he raised the issue in Parliament on Monday.

“More than 3,000 people paid EI premiums only to have the government deny them support just when they needed them most,” he said during question period.

“Conservatives promised to fix this situation, so why are they still denying these women the sickness benefits they paid for and that they deserve?” he added.

Minister of Employment and Social Development Pierre Poilievre responded that his “heart goes out to anyone in these difficult circumstances.”

“That’s precisely why our government introduced legislation,” said the Conservative MP, “to ensure that people who do fall ill while they are on EI parental leave can get it.”

The government has paid sick leave benefits to those on parental leave ever since their Helping Families in Need Act came into force in March, 2013, but the new law did nothing to compensate thousands who were refused during the previous decade.

In fact, the government spent $1.3 million trying to prevent McCrea’s class action from going ahead.

Kasbohm wonders why the government would want to take on mothers with babies, “and especially mothers (who) are sick.”

“That just makes it look even worse on their end.”

With a report from CTV’s Richard Madan