Seniors can start enrolling in the new Medicare (search) discount drug program beginning Monday by going to the Web site or dialing a 1-800 number.

"I'm telling you that once we get this up and running, which we are, it's going to be very effective," said Health and Human Services Secretary Tommy Thompson.

The Bush administration has been pushing the new program, launching an $18 million advertising campaign. It is promoting the expected cost-savings to seniors, who can begin using the cards on June 1.

Seniors can choose from among 70 card options — based on where they live, their income and the pills they take. Health and Human Services (search) officials say Medicare recipients can expect an average savings of 10 to 25 percent on the retail price for most drugs. 

But senior Democrats, including Sen. Ted Kennedy (search), are slamming the discount cards.

"The millions of taxpayer dollars that the Bush administration is spending to hype a phony card would be better used for bus tickets for seniors to buy cheaper prescription drugs in Canada," Kennedy of Massachusetts said.

Click here to watch a report by Fox News Channel's Catherine Herridge.