ALBANY – Governor Pataki is likely to include money in his executive budget for education tax credits that would go to parents of students in both public and private schools.

If New York approves such a dollar-for-dollar tax credit, it would be one of a small but growing number of states to adopt what is widely viewed as a less controversial alternative to school vouchers. The state could lose hundreds of millions of dollars in revenue if the program is implemented, but some of the costs could be offset if students leave public schools to attend private or parochial schools. The government spends between $10,000 and $20,000 for each public school student, while the tax credits would be capped at $1,500 a student.

Mr. Pataki hinted about the tax credits in his State of the State speech last week when he told lawmakers he wanted Albany “to give parents the chance to give their kids the tutoring, after-school programs, and other educational opportunities they need to succeed.”

Proponents of education tax credits, many of whom also favor vouchers, say the credits would be less powerful than vouchers but would still give low-income parents more choices about where to send their children to school. The tax credits have a better chance of getting by state courts, many of which have ruled vouchers unconstitutional. In recent months, Catholic and some Jewish groups, whose members could use the credits to help offset the costs of parochial school tuition, have been pressing hard for Albany to pass the measure. The groups are planning a rally in front of the Capitol next month.

Opponents of the credits, such as the United Federation of Teachers, view them as vouchers in sheep’s clothing. The union says it fears the tax credits would siphon money from the public school system.

Lawmakers in both houses of the state Legislature last year introduced legislation that would give parents tax credits up to $1,500 a student or $3,000 a family that could be used to pay for educational expenses such as the ones highlighted by the governor in his speech. Support for tax credits is strong in the Republican-controlled Senate but much shakier in the Assembly, where teachers unions are influential campaign contributors to the Democratic majority.

The president of the UFT, Randi Weingarten, told The New York Sun she predicts New York courts will rule against “anything that looks like vouchers,” and said that for Mr. Pataki to “do something that you know won’t have legal traction is simply diversionary.” She said Mr. Pataki would be better off spending money on programs that are proven to be effective, like the funding of full-time preschool for 4-year-olds, than spending money on “concepts that may play well in other states or with other audiences” – an apparent reference to the governor’s presidential ambitions.

The most powerful Democrat to back the plan is Vito Lopez, a veteran assemblyman who was just elected chairman of the Brooklyn Democratic Party and who represents a district with a Catholic majority. The Roman Catholic diocese of Brooklyn, which has had to shutter several Catholic schools in the area because of declining enrollment it attributes to increased tuition, has leaned heavily on Mr. Lopez to get behind the tax credits. Mr. Lopez saw the number of Catholic schools in his district fall to four from seven in the past year.

A spokesman for the Assembly speaker, Sheldon Silver, a Democrat of Lower Manhattan, said Mr. Silver would look at tax credits in the context of the larger budget. Mr. Silver has come out against school vouchers.

A spokesman for the governor’s budget division, Scott Reif, refused to comment on the governor’s position on education tax credits or whether they would be included in the budget, which Mr. Pataki is set to unveil next week.

In the Senate bill, which is sponsored by Martin Golden, a Republican from Brooklyn, the maximum level of credit, $1,500 a student for a maximum of two students, would be given to families with adjusted gross income less than $40,000 a year. For families with income between $40,000 and $100,000, the credits would be determined under a sliding scale starting at $1,000 per student and going down to $500 a student. Families with higher earnings would not be eligible. The plan would be phased in beginning with the earliest grades and would cost the state, or save families, $460 million annually, according to the text of the bill.

Under the proposed legislation, eligible expenses on which families could spend the money include fees or tuition expenses, tutoring, summer camps, textbooks, computers, and educational software. The Senate bill also gives teachers a maximum annual tax credit of $250 to buy school supplies.

The most serious threat to vouchers in America has come from the so-called Blaine amendments, which more than half the states adopted in the 19th century during a period of high anti-Catholic sentiment. The amendments bar the public funding of religious institutions. Proponents of education tax credits say the measures offer relief to parents but avoid the legal obstacles, like the Blaine amendments. Lawmakers in New York, which has its own Blaine amendment, have largely avoided the issue of vouchers.

Among the states with education tax credits are Arizona, Pennsylvania, Illinois, Florida, and Iowa, according to Adam Schaeffer, a researcher at the American Enterprise Institute, a think tank based in Washington, D.C.

In Arizona, the state’s highest court has ruled that tax credits do not violate the First Amendment’s Establishment Clause or the state’s Blaine amendment, and has permitted the government to offer families tax credits that can used to fund programs that give scholarships to private schools. In Florida, Governor Bush is trying to build support for a plan that would provide tax credits to corporations that offer scholarships, after the Supreme Court last week struck down a statewide voucher program.

Tax credits “have survived more tests than have vouchers,” Mr. Schaeffer said. “Voucher money comes directly from the government funds, while education tax credits in past rulings have not been considered government funds because they are never in the government’s control.”

The director for education of the New York State Catholic Conference, James Cultrara, said the tax credits would relieve the state of some of the burden of funding public education by allowing more students to attend private schools.