SPRINGFIELD - A group of House Democratic lawmakers announced Thursday they want to ask voters to amend the state constitution to double the income tax burden on Illinoisans who earn more than $250,000 a year.

The amendment would not only reform the Illinois tax structure, which is one of only seven states nationally with a flat tax rate, but would also specify that the money be spent in equal parts on education, a construction plan, and tax relief for lower-income families.

State Rep. Mike Smith, D-Canton, will sponsor the proposed amendment, which he said will bring in an estimated $3 billion a year and will achieve the goals of education funding and a construction plan.

"I believe a flat rate income tax is a regressive tax, it's an unfair tax and by moving to a progressive tax - one that taxes those who earn more at a higher rate - we can accomplish some of these goals that have eluded the state for a number of years," Smith said at a press conference at the capitol.

Smith said about 107,000 of the more than 5 million taxpayers in Illinois would be affected by the proposed increase.

In order for the Illinois Constitution to be amended, both chambers of the General Assembly must approve the proposal by a three-fifths majority. Afterward, 60 percent of voters must vote in favor of the amendment on a referendum that will appear on the ballot in the next election.

In addition, the proposal must be approved by lawmakers at least six months before the election or it cannot appear on the ballot - which means that both the House and Senate must approve it by the beginning of May in order to be on the November 2008 ballot.

State Rep. John Bradley, D-Marion, supports the proposed amendment.

"It's a tight deadline, and these are tough times financially for the state and for everyone," Bradley said. "This is a realistic opportunity to allow the people of the state of Illinois, through a democratic process, to decide whether we go in a certain direction in this state."

State Rep. Pat Verschoore, D-Milan, said the proposal is a more reliable approach than the large expansion of gambling that has been discussed as a solution for the state's construction woes.

"I'm for gaming, but gaming is up and down - you never know," Verschoore said. "This would be a constant every year. It's good when you have a constant revenue stream - you can count on things, you can plan things."

The representatives shrugged off questions of whether or not the spending was written into the amendment to circumvent the governor's office, which would normally decide how to release funds.

Bradley said a constitutional amendment represents the most the General Assembly can do to ensure the funding.

"To the extent we can lock this thing down, we're going to do it constitutionally," Bradley said. "If the administration or the judiciary chooses not to abide by the Constitution, we've got bigger issues."

A spokeswoman for Senate President Emil Jones, D-Chicago, said there is no certainty on whether or not there will be support for the proposal should it reach the Senate.

The legislation is House Joint Resolution Constitutional Amendment 42.

Super rich in Illinois

Chart shows the number of people who make more than $250,000 annually in select counties based on 2005 figures. Source: Illinois House Democrats.

Cook - 45,156; Will - 2,593; Whiteside - 148; Rock Island - 578; Henry - 121; Mercer - 33; Livingston - 115; Woodford - 163; Tazewell - 586; McLean - 804; Ford - 19; Logan - 49; DeWitt - 44; Piatt - 55; Macon - 520; Christian - 66; Moultrie - 50; Douglas - 27; Coles - 145; Shelby - 32; Randolph - 51; Perry - 14; Franklin - 50; Hamilton - 6; White - 35; Jackson - 157; Williamson - 151; Saline - 59; Gallatin - 13; Union - 39; Johnson - 5; Pope - 3; Hardin - 3; Alexander - 5; Pulaski - 4; Massar - 17.