An Ontario woman who sought treatment for a growth in her brain in the United States is now the poster girl for a campaign to prevent universal health care south of the border, telling Americans in television ads that she would have died if she had waited to be treated in Canada.

Shona Holmes, of Waterdown, Ont., was treated for a growth near her pituitary gland at the famed Mayo Clinic after doctors in Canada told her she would have to wait several months for a referral to a specialist.

She re-mortgaged her home and paid about $100,000 for treatment.

She is now a spokesperson for the Center for Medicine in the Public Interest's BigGovHealth campaign, which warns Americans that, "Increased government control and bureaucracy over our health care will come at great risk to American patients, consumers and health care workers."

The controversial television ad is sponsored by Patients United Now, a citizens' group that opposes government-run health care.

In the ad, which is running in all 50 states, Holmes tells viewers that she "survived a brain tumour, but if I'd relied on my government for health care, I'd be dead."

The ads go on to claim that Canadians wait a long time for care, are denied care or cannot access some drugs or treatments, "because the government says patients aren't worth it."

Holmes defended her appearance in the ad, saying she wanted to warn both Canadians and Americans, tens of millions of whom do not have health insurance, that many patients in Canada are falling through the cracks.

"Absolutely everybody deserves healthcare, there's no question," Holmes told CTV's Canada AM on Wednesday. "I think where the problem lies is that I'm really not comparable to the (patients) who are uninsured because I am insured, I had coverage. What I didn't have is access...this is what I'm concerned about, is that by providing everybody insurance, doesn't mean that everybody gets access."

Liberal MP and former health minister Ujjal Dosanjh has appeared on American talk shows over the past few days to counter the anti-universal health care message.

He told Canada AM on Wednesday that while patients do have to wait for some procedures, urgent issues "are treated fairly quickly."

"I think one of the things that we need to keep in mind is that Ms. Holmes may be an exception to the rule," Dosanjh said. "We shouldn't let extreme exceptions that can happen in any system define the entire system. We, according to her, have a wonderful healthcare system, and what we need to do is improve it."

The issue has exploded in the U.S. since President Barack Obama took office in January. Obama wants to overhaul the American health care system and expand coverage to the roughly 50 million Americans who do not have insurance.

The U.S. president is facing stiff opposition from both Democrats and Republicans and will take his case to the American people Wednesday night in a prime-time news conference.

Meanwhile, Holmes has tried to recoup some of the money she spent to get treatment in the U.S. The Ontario Health Insurance Plan (OHIP) denied her original claim and she has a hearing on the matter scheduled in September.

Holmes admitted that patients receive "wonderful care in Ontario," and said it was not an easy decision to seek care south of the border.

"I think it's very, very odd for any Canadian to feel that they have to leave their country to find out what's dramatically wrong with them."