California state Senate President Darrell Steinberg (D), left, with Gov. Jerry Brown (D), center (Photo: Ken James/Bloomberg)

Hundreds of thousands of low-income children would gain access to pre-school education under an agreement struck by legislative leaders in Sacramento this week in a compromise announced Thursday.

The proposal, still making its way through the legislature, would provide hundreds of millions of dollars to offer preschool access to 234,000 low-income four-year olds, state Senate President Darrell Steinberg (D) said Thursday. Four-year-olds from low-income families with at least one working parent would be eligible for full-day pre-kindergarten.

Tens of thousands of additional students would have access to so-called “transitional” programs. Those programs are reserved for children born between Sept. 1 and Dec. 1, who would be younger than their peers when they enter kindergarten programs.

The agreement allocates $85 million for Fiscal Year 2014-2015, which begins July 1, and creates 11,500 new full-day, full-year pre-school slots for low-income children. An additional 31,500 slots would be created next year.

Another $85 million would go toward improving pre-school quality, including $50 million in grants to local school districts and $35 million in one-time funding for professional development for teachers.

“It is smarter and more prudent to make this investment in success up front, rather than paying for the costs of failure at the end,” Steinberg said Thursday.

The deal will eventually cover more than half of all four-year-olds in California. Steinberg and legislative Democrats had called for universal pre-kindergarten earlier this year, after California tax collectors reported surging revenue fueled largely by capital gains taxes. That program would have cost about $1.5 billion per year.

But Gov. Jerry Brown (D) balked, and left the universal program out of his budget proposal. The two sides negotiated down to a total cost of $264 million for the first year.

The “Fair Start” pre-school proposal, as it’s known, passed a bicameral budget conference committee by a 7-1 vote on Thursday. The state Senate and Assembly will take on the full budget proposal on Sunday. Brown’s office has not signaled whether he will sign or veto the budget.

Lawmakers are required by law to pass a budget by June 15. If they fail to pass one by Sunday, their pay will be withheld. Brown can still exercise a line-item veto once the budget reaches his desk.

Legislators and Brown’s office also debated how to spend money generated by the state’s cap-and-trade program. Democrats in the legislature wanted to use the money for affordable housing and public transportation, while Brown wanted to use some of the money to fund his proposed high-speed rail project.

Legislators agreed to provide 25 percent of cap-and-trade revenue to the rail project, short of the 33 percent Brown initially sought. Cap-and-trade revenue is expected to generate as much as $1 billion during the coming fiscal year. Fifteen percent of that revenue would go to other transportation projects and 20 percent would go to housing and reducing greenhouse gases.