A Canadian woman married to a British man has been deported from the United Kingdom because of a British law aimed at preventing forced marriages.

Rochelle Wallis, 19, boarded a flight at Heathrow airport on Wednesday to travel to Calgary where she will be met by her mother, with whom she will be living in Revelstoke, B.C.

"It hasn't really set in, to be honest," Wallis told CBC News while waiting to check in at the airport. "I can imagine once it does, I'm going to be quite devastated."

Her Welsh husband, Adam Wallis, 28, echoed her sentiments.

"It's not going to sink in until she's walking through those gates, but I'm still feeling really terrible," he said.

Wallis, formerly Rochelle Roberts, met Adam when he was in British Columbia in 2006, and they fell in love. Wallis had the necessary visa to be in Britain at the time the couple married in November 2008 in Adam Wallis's village of Pontrhydygroes, Wales.

The couple's marriage application was filed a month before Wallis's six-month visa expired, but wedding plans had to be delayed after officials lost their passport photos.

By the time the couple wed, she had outstayed her visa, meaning she had to return to Canada and apply for a spousal visa before going back to Wales.

But Britain's new Forced Marriages Act, which raised the age individuals could apply for spousal visas from 18 to 21 for anyone outside the European Union, was in effect by then.

The law is intended to stop young girls and women from South Asia from being brought into the U.K. against their will and forced into arranged marriages.

"Rochelle entered into this union completely voluntarily," said CBC correspondent Ann MacMillan. "The irony is if Adam had married someone from Poland or Portugal — EU countries — there would be no problem."

Home Secretary Allan Johnson wrote to the couple to order Wallis to leave Britain or be forcibly deported, the BBC reported.

The case has caught the attention of the British media and several members of Parliament.

'Sensible thing to do'

Labour MP Keith Vaz, who chairs Parliament's home affairs select committee, is backing the couple.

"I think the home secretary ought to have used his discretion, which he has, to allow Rochelle to stay in this country," Vaz told CBC. "She's clearly not a threat to national security, and therefore, that would have been the sensible thing to do.

"These laws were brought in to stop forced marriages — the fear people under the age of 21 were being forced to marry people just to come into the United Kingdom, This is clearly not the case," Vaz said.

A Home Office spokesperson told the BBC the benefits of the law outweigh the drawbacks and the possibility of cases similar to Wallis's situation.

Wallis will still be able to apply for the spousal visa when she arrives in Canada, and if it's declined, as expected, she can appeal the decision on grounds that it violates her human rights.

The couple has sought legal advice but because of the time and money involved in such a legal challenge, the two are not sure they will be pursuing that option, MacMillan said.

Though the two could also move to another EU country and live together until she turns 21, their current plan is to join each other for holidays in Europe until she is old enough to have her spousal visa approved, MacMillan said.