The CRTC is increasing capacity for its "Do Not Call" list website after it was overwhelmed by thousands of interested Canadians trying to block telemarketers.

The website slowed down due to the heavy traffic, but is now "slowly getting better," CRTC spokesperson Denis Carmel told ctvtoronto.ca on Tuesday.

People could access the website again after about 3 p.m., although the phone line rang busy.

The CRTC said about 223,000 people had registered for the service by about 1:30 p.m. Tuesday. More than one million people tried to access a telephone hotline to register. The site and hotline were activated at 12:01 a.m.

"We are victims of our own success," said Carmel. "At one point, 18,000 tried to get through at the same moment. If you would have told me these numbers yesterday, I would have laughed. It's phenomenal."

Canadians began to complain early Tuesday morning as they tried to register for the service. The site worked sporadically throughout the morning but not everyone was able to register. At certain points, a posted message on the site said it was "unavailable due to planned maintenance activities."

Calls to their automated hotline were also unsuccessful as many people couldn't get through.

Carmel said they are currently increasing bandwidth on the site and working to get additional phone lines activated. He also said that people should keep trying throughout the day and the rest of the week to sign up.

"People can sign up at any time, it doesn't have to be today," he said.

Carmel said they were anticipating 100,000 registrants in the first week after reviewing a poll that said only 51 per cent of Canadians were aware of the registry.

However, other polling has shown that about two-thirds of Canadians would like to be on such a list.

The Do Not Call list will prevent telemarketers from calling people who put their phone numbers on the registry. However, it won't block charities or pollsters from contacting people.

Though the service was launched Tuesday, it won't take effect until 31 days after a person has registered.

To sign up for the service, please visit www.dncl.gc.ca.

With a report from CTV Toronto's Galit Solomon