The plan, unveiled by Reps. David Obey, D-Wis., John Murtha, D-Pa., and Jim McGovern, D-Mass., would require low- and middle-income taxpayers to add 2 percent to their tax bill. Wealthier people would add a 12 to 15 percent surcharge, Obey said.
Top Democrats immediately shot down the idea and Republicans roasted Democrats for linking funding for U.S. troops overseas with tax increases.
"Just as I have opposed the war from the outset, I am ... opposed to a war surtax," said House Speaker Nancy Pelosi, D-Calif.
"If the new majority has proven one thing this session, it's that no piece of legislation is immune from being converted into a vehicle to raise taxes," said Rep. Roy Blunt of Missouri, the GOP whip.
Democrats have been seeking in recent weeks to contrast the approximately $190 billion cost of the Afghanistan and Iraq wars with the $23 billion increase that Democrats want in domestic programs.
President Bush has threatened to veto most of those domestic spending bills as too expensive. Those bills were largely written by the House Appropriations Committee that Obey chairs. Murtha chairs the panel's subcommittee that writes Pentagon and war spending bills.
"The war will cost future generations billions of dollars in taxes that we're shoving off on them and it is devouring money that could be used to expand their educational opportunities, expand their job training possibilities, attack our long-term energy problems and build stronger communities," Obey said.
At the same time, a group of Democratic allies, including unions and liberal advocacy groups such as MoveOn.org and Americans United for Change, announced a grassroots and an advertising campaign urging Republicans to override Mr. Bush's promised veto of a bill expanding a popular children's health insurance program known as SCHIP.
The $3 million to $5 million campaign will be broadened to upcoming battles over domestic spending, including a measure boosting spending on education, health research and job training programs.
"SCHIP and the battle over spending priorities is the most important fight since the showdown over privatizing Social Security," said Gerald McEntee, president of the American Federation of State, County and Municipal Employees. "I don't think we need to remind Bush who won that battle."
But Republicans pounced on the tax surcharge idea.
"Americans will reject Democrat plans to take away their hard-earned dollars and will penalize the party that demonstrates an inability to win the War on Terror," said Republican National Committee spokesman Danny Diaz.
Obey also announced that Democrats will not pass a supplemental spending bill for the Iraq war until next year, when Democrats hope public pressure could force Mr. Bush to change the course of the war.
Democrats hope their chances of winning a battle with Mr. Bush on the war will be better next year as the election season heats up.
"The showdown is going to be in January or February," McGovern said.
The lawmakers said the tax surcharge was similar to policies put in place to pay for the Vietnam War and World War II.
"By putting together this bill we hope people will stop ignoring what this war is costing American taxpayers and call the president's bluff on fiscal responsibility," Obey said.