Christian Martin and Paula Critchley are fighting an arbitrator's decision that denied their double claim of parental leave benefits. (CBC)

An Ottawa couple who were denied double parental benefits to care for their twin girls are taking their case to the Federal Court of Appeal.

Christian Martin and his wife Paula Critchley both applied for the full 35 weeks of parental leave after the births of their daughters, Lucie and Athena, in April 2009.

Normally, under Canadian law, the parents may take a total of 35 weeks of parental leave following a birth or adoption while receiving benefits under Canada's Employment Insurance program, no matter how many children are born to or adopted by the parents at the same time.

But Martin and Critchley had argued that since parents of children born a year apart are entitled to two 35-week benefit periods, parents of twins should receive the same amount of time.

In September 2009, a board of referees of the Canada Employment Insurance Commission awarded the couple 35 weeks each — one for each child.

But in May this year, an arbitrator overturned that decision, saying the Employment Insurance Act is clear that benefits were limited to 35 weeks for "the care of one or more new-born or adopted children as a result of a single pregnancy or placement."

Martin said they are appealing, arguing the law is inconsistent and violates their right to equality under Canada's Charter of Rights and Freedoms.

"They say on one hand that it's based on pregnancy, but in fact it isn't, it's based on caring for a child," said Martin, arguing that mothers who give their babies up for adoption are not entitled to the benefit while those who adopt are.

"But they use that pregnancy provision to prevent people like me to be able to obtain benefits. It's only used in that instance, so it's a double standard," Martin said.

"It's unfortunate because they are not applying their own law properly," he said.

Martin said he is reaching out to other families to help fund his fight to the next stage at the Federal Court of Appeal.

Monique MacKenzie, mother of twin girls, said she sympathizes with the case after caring for her infant daughters alone for many months.

"I had my mom for a few months, but I did do a couple months all on my own and almost went insane," MacKenzie said. "If we had them one at a time, they would have been paying EI times two years."

Martin said he hopes the case will lead Parliament to reconsider whether multiple births deserve multiple benefits.

With files from the CBC's Alistair Steele