Washington (CNN) - Senate Democrats Wednesday unveiled a five percent tax hike on annual income over $1 million, which they said would raise the nearly $450 billion needed to offset the cost of President Barack Obama's recent proposal to boost employment and stimulate the economy.

However, the idea was met with a not-unexpected thud by Senate Republicans who steadfastly oppose tax increases and indicated it won't pass the narrowly divided chamber.

"We're going to move to have the richest of the rich to pay a little bit more," said Senate Majority Leader Harry Reid, D-Nevada, at a Capitol news conference.

Senate Minority Leader Mitch McConnell, R-Kentucky, immediately said he and his colleagues would block any tax increases.

"We don't think raising taxes in the middle of a recession is a good idea," he told CNN. "I think we made that pretty clear in the past."

The Democrats' plan would place a surtax on any income earned over $1 million. That would include earned income - like salary - and unearned income - like profits from dividends or the sale of stocks. Taxes on estates worth more than $1 million would also be subject to the surtax.

The new Democratic plan would replace a not fully-defined proposal from the president to pay for the jobs plan. It was unpopular with some Democrats because it included tax hikes on the wealthy and on corporations like oil and gas companies.

"An overwhelming majority of Democrats" support the plan, said Sen. Chuck Schumer of New York, a Democratic leader.

Top Senate Democrats acknowledged it might be difficult to win GOP support for the bill, but said they hoped public opinion surveys that show broad support for increasing taxes on the wealthy would persuade Republican senators.

"They have to listen to their constituents," Reid said.

Reid is expected to move the bill as early as next week, but senior aides acknowledged Republicans will likely defeat the measure on a procedural vote before the bill even makes it to the floor.

Asked about the Senate Democrats' proposal, House Democratic Whip Steny Hoyer said Wednesday, "I think that has support here in the House."

"I think we'd be very pleased to support it, and in fact some of our members may like that alternative better," Hoyer added, saying, "I'm sure that's the case as a matter of fact" but he acknowledged he hasn't canvassed all House Democrats on the proposal.