HARRISBURG — Nearly two-dozen advocacy groups are pushing the governor and state lawmakers to increase aid to public schools and distribute the money more equitably among school districts — a goal that has eluded policymakers for decades.

The Pennsylvania School Funding Campaign, which was announced Wednesday, has new ammunition fueling its activism: a state-funded school cost study released in the fall. The study identified a nearly $5 billion a year gap between current education spending and the amount needed for all children to meet the state's academic standards.

Leaders of the participating groups said the campaign marks the first time they have coordinated their lobbying on the issue.

"We're going to make sure that every legislator gets visited by a constituent," said Joan Benso, president and chief executive officer of Pennsylvania Partnerships for Children. "We're going to make it the No. 1 issue in the state Capitol this spring, and we're not going to go away until it's over."

The campaign is calling for the inclusion of at least $1 billion in the 2008-09 state budget as a first step toward revising the school-funding formula by 2013.

Critics have long argued that the formula relies too heavily on local property taxes and provides inadequate assistance to needy districts. The state's basic-education subsidy covers roughly one-third of public school costs on average.

The coalition has also developed a formula that would determine how much state money each school district should receive, factoring in its wealth and its ideal per-pupil spending level calculated by the study. The proposed formula also would limit the local tax bill for education to 2.7 percent of a household's personal income, with the state increasing its education spending to maintain that cap.

Fully funding the formula would cost the state $5.7 billion a year, said Jane Carroll, a former state Education Department school finance official who is now a senior fellow with the Education Policy and Leadership Center's Education Finance Project.

"It is fairer because it is based on taxpayers' ability to pay, not the value of their property," Carroll said.

Members of the campaign include statewide associations that lobby for school boards, administrators, and teachers' unions; religious groups such as the Pennsylvania Council of Churches; and the Pennsylvania PTA.

Gov. Ed Rendell's spokesman Chuck Ardo said the administration wants to evaluate how well the group's proposal meets certain criteria, such as whether it can be realistically implemented in the state budget, before taking a position on it.

The state currently spends more than $9 billion a year on basic education.