Senate Democrats on the Appropriations Committee broke with the Obama administration today to provide additional funding for a controversial school voucher program in the District of Columbia.

Republicans pushed for more money to be spent on the initiative during the committee’s markup of its fiscal 2013 spending bill for financial services and general government, which contains D.C.’s budget.

It sets up an interesting dynamic surrounding an issue that does not break neatly along party, or chamber, lines.

The D.C. Opportunity Scholarship Program was established in 2004 as a five-year pilot program to give almost 1,000 vouchers to District students to attend private or parochial schools around the city. It was reauthorized in the fiscal 2012 spending deal after a two-year lapse, with Speaker John Boehner (R-Ohio) championing the cause with Sen. Joe Lieberman (I-Conn.).

D.C. Del. Eleanor Holmes Norton (D) and her House allies have fought against continuing the program, arguing that it wastes precious dollars on a small population of the D.C. education system that could be poured into public and charter schools in need of additional resources.

President Barack Obama agrees; in his fiscal 2013 budget request, he proposed no new funding, leaving the program to float itself on the funds its currently has. It wouldn’t cover enrollment for new students, only those filling spots left open through attrition.

Democrats on the Senate Appropriations Committee, however, opted to give the program an additional $13.5 million.

The money, according to the report accompanying the spending bill, would support “a potential net increase of 610 students or 38 percent more scholarship participants than the 1,615 students in school year 2011-2012.”

Language added during the bill’s markup by Sen. Dianne Feinstein (D-Calif.) would further emphasize that new students would be admitted into the program under the funding level provided.

But Ron Johnson (R-Wis.) argued that the funding request ran afoul of statute. He said the law specifies that D.C. public schools, public charter schools and the school voucher program should all receive $20 million apiece. But the committee’s budget would only grant the voucher program $13.5 million.

“All I’m asking is that this committee recognizes what the law is,” Johnson said. “The law directions the Opportunity Scholarship Program to equal the funding offered to public schools and charter schools.”

Sen. Dick Durbin (D-Ill.), chairman of the Subcommittee on Financial Services and General Government, pointed out that the program still has $34 million it has not yet spent.

“We’re basically saying ... ‘We want you to have enough money, keep going, expand the program, but since you’re sitting on $34 million, we’re not going to send you additional money until you’ve expended it,’” Durbin said. “We’re not trying to pull any tricks here. A good conservative like you out to be saying, ‘Why would we be sending them more money when they haven’t spent what we already sent them?’”

Johnson’s amendment would have inserted language into the committee report clarifying that public schools, charter schools and the voucher program should all receive equal funding levels. It was defeated, 13-17.

The House Appropriations Committee is set to consider its fiscal 2013 spending bill as early as next week, and it would likely include the full $20 million for the program in deference to Boehner.

Though Norton has been a staunch opponent, fighting vigorously against her chamber’s efforts to reinstate the program through stand-alone legislation last year by saying that D.C. residents were not Congress’ “lab rats,” she has not yet commented on efforts to bulk up funding for the program.

In a statement released this afternoon after the markup’s conclusion, Norton thanked Senate appropriators for a “clean” bill free of “anti-home-rule riders,” such as a ban on local funding for abortion, which is in the House version.

Correction: 3:32 p.m.

An earlier version of this article mischaracterized what an amendment by Sen. Ron Johnson (R-Wis.) would do. It would have inserted language clarifying that public schools, charter schools and the voucher program should all receive equal funding levels.