Advocates of a business tax credit that would support private and public education hope that the Archdiocese of Baltimore's plan to announce school closings this week will heighten the sense of urgency about the legislation before the General Assembly.

Supporters of the tax credit bills will rally outside the State House in Annapolis on Wednesday morning as a preamble to an afternoon Senate committee hearing.

The Senate and House legislation - which would give Maryland businesses a 75 percent state tax credit for donations to organizations supporting scholarships and school programs - has been introduced four times before. Rallies have been held every year in early March.

Mary Ellen Russell, executive director of the Maryland Catholic Conference, said she hoped that word of the archdiocesan plan to close some of its 64 schools and merge others "has a tremendous impact on the General Assembly. ... It's demonstrating what we've been saying for years about the need for this legislation."

Russell doesn't believe that the legislation alone would solve the problems of rising tuitions and falling enrollments that has prompted the Catholic school consolidation. Details of the reorganization - which the archdiocese pledges will not displace any of the 22,700 students now enrolled - are to be announced to principals, teachers and parents Wednesday with a public announcement Thursday.

The legislation is "not a silver bullet. ... Nobody is expecting the solution to be easy," Russell said. She said the tax credit "would give hope to everyone that there would be relief for school families."

The legislation was passed 30-17 by the Senate two years ago, but it has never advanced on the House side beyond committee hearings, Russell said. She said the bill has "broad bipartisan support," but is being blocked by the House Ways and Means Committee, which has never voted on it.

Democratic Sen. James E. DeGrange Sr. is the chief sponsor of the Senate bill, which has eight backers. Democratic Del. James E. Proctor Jr. is the chief sponsor in the House, where the bill has 75 supporters.The measure has been opposed consistently by the Maryland State Education Association, the state's largest teachers' union with 71,000 members. Union spokeswoman Debra Garner said the organization argues that a tax credit would divert public money from public schools.

"We believe that any money that comes from taxpayers ought to be set aside for public schools," said Garner.

According to a coalition of supporters called Building Opportunities for All Students and Teachers in Maryland, or BOAST, the identical Senate and House bills include tax credits for programs that support public school "enrichment" programs. Those programs are activities that are not part of the regular school curriculum, including field trips and extra classes after school and on weekends.

The measure would also support scholarships for children whose families cannot afford private school tuition.

That's been a particular problem for Catholic schools in many older urban areas, as more affluent families have left the cities for the suburbs, leaving behind low-income families who would send their children to Catholic schools if they could afford to. The cost of tuition has risen steadily as Catholic schools have had to pay lay teachers to replace the nuns who used to work for virtually no pay.

Those working on the Baltimore archdiocesan school consolidation and a separate long-term financial security plan have mentioned the tax-credit legislation as part of a solution that would also probably include more fundraising, stronger ties with alumni and marketing.

Six states - Arizona, Florida, Georgia, Pennsylvania, Indiana and Rhode Island - have adopted similar legislation.