WASHINGTON —  Tight school budgets have meant fewer teachers, larger classes and shorter school years, according to a White House report that President Barack Obama says shows the need for Congress to pass his proposals to help states reduce teacher layoffs.

The study concluded that 300,000 education jobs have been lost since the official end of the recession in 2009 and that student-to-teacher ratios have increased by 4.6 percent from 2008 to 2010 and are on track to grow more.

“If we want America to lead in the 21st century, nothing is more important than giving everyone the best education possible — from the day they start preschool to the day they start their career,” Obama said in his weekly radio and Internet address Saturday.

For Obama, the report offered a fresh chance to push a nearly year-old jobs plan he proposed that provided money for states to keep teachers, police officers and firefighters on the job. The proposal included payroll tax cuts and jobless insurance provisions that Congress has passed. But other proposals in the plan have run aground amid mostly Republican opposition.

Obama is pressing Congress to act, part of an election-year strategy to portray Republicans as obstructionists. Republicans have proposed their own measures, but they have not advanced in the Democratic-controlled Senate. The partisanship has created a stalemate that Obama has tried to exploit during his re-election campaign.

While the private sector has continued to create jobs, though at a sluggish pace, the public sector has been posting monthly job losses, contributing to an 8.3 percent unemployment rate.

Obama’s plan includes $25 billion in aid to prevent layoffs of teacher and pay for other education jobs. That is part of a broader effort to retain state and local government jobs.

The White House report was not a product of the Education Department. It was prepared by the president’s Council of Economic Advisers, his Domestic Policy Council and his National Economic Council.

According to the report, average student-to-teacher ratios reached a low of 15.3 in 2008 but climbed to 16 students per teacher in 2010, equal to levels in 2000. The report acknowledges that typical class sizes are actually larger than those ratios because the measures include teachers for students with disabilities and other special teachers who are excluded from class size counts. It said that in many districts, class size is much higher because of steeper cuts in education budgets.

The report says that since the fall of 2010, local governments have cut about 150,000 more education jobs.

In the address, Obama said a House Republican budget would make conditions worse because it would cut further into education spending to help pay for new tax cuts for the wealthy.

“That’s backwards,” he said. “That’s wrong. That plan doesn’t invest in our future; it undercuts our future.”

That’s an argument Obama has been making on the campaign trail against Republican rival Mitt Romney and his running mate, Paul Ryan, the author of the House budget.

In the Republican address, Rep. Vicky Hartzler of Missouri criticized Democrats and the president for Congress’ failure to restore disaster programs for farmers suffering from the worst drought in 25 years.

“A lot was riding on this bill, but the Senate, a body controlled by the president’s party, left Washington for the month of August without even bringing it to a vote,” she said. “The president has seen fit to politicize this issue, but the fact is he didn’t urge the Senate to act.”

The legislation was all the Republican-controlled House could pass amid Republican divisions over farm subsidies and food stamps in a broader food and farm policy bill. The Senate would not act on the pared-down bill, insisting that Congress consider a full five-year extension of the farm legislation with 80 percent of it, or about $400 billion, devoted to food stamps.