Washington (CNN) -- First lady Michelle Obama's push for a new child nutrition law has hit a wall in Congress -- at least temporarily.
Democrats on both sides of the issue say the legislative overhaul she's advocating is nearly frozen in the House of Representatives and very unlikely to pass before lawmakers recess this week.
A key bloc of House Democrats is threatening to vote against the Senate-passed child nutrition bill the first lady is promoting because it pays for the new initiatives in part by taking $2.2 billion slated for the food stamp program.
A spokesman for Rep. Jim McGovern, D-Massachusetts, told CNN Radio Wednesday their office thinks the measure probably won't clear the House before the election break. McGovern has said he could support the bill if the White House gives strong assurances to House Democrats that it will replenish the food stamp money, which goes to low-income families.
"We're not going to tolerate robbing the poor to pay for every piece of legislation," McGovern told CNN Tuesday.
That kind of opposition from McGovern and others seems to have killed any momentum for the bill. A Democratic leadership source supporting the measure admitted Wednesday morning that there was no more behind-the-scenes action on the bill, indicating it will be shelved.
That would leave only one more window for passage -- when Congress returns after the election for a so-called "lame duck" session.
If the House doesn't pass the bill before September 30, the end of the fiscal year, the current nutrition programs will get a short-term extension of funding in the bill that Congress is expected to pass this week before members leave to campaign.
An aide to the first lady tells CNN that Mrs. Obama has been personally making phone calls to House Speaker Nancy Pelosi and other House leaders, and her staff has pressed the issue in regular meetings on the issue. The aide would not say exactly how many calls she has made.
The first lady's push has involved other key figures at the White House as well. Chief of Staff Rahm Emanuel called McGovern last week, McGovern's office confirms, to try and win his support for the bill.
The first lady has also taken the fight on the road, publicly calling on the House to pass the Senate bill in a speech in New Orleans, Louisiana, recently. She has similarly pressed the Congressional Black Caucus and Congressional Hispanic Caucus in remarks to those groups this month.
While careful to praise the first lady's focus on the issue, McGovern slammed Senate Democrats for using money from the Supplemental Nutrition Assistance (SNAP) program to pay for the $4.5 billion nutrition bill. House liberals support the programs in the Senate bill, but feel burned after reluctantly voting this summer to take significant money from the food stamp program to pay for legislation that sent money to cash-strapped states to avoid teacher layoffs.
House liberals are now drawing the line at doing that again. "The SNAP program shouldn't be an ATM," McGovern said. He and another 105 House Democrats sent a letter to Pelosi last month criticizing the Senate's bill, stating "this is one of the more egregious cases of robbing Peter to pay Paul, and is a vote we do not take lightly."
A frustrated McGovern noted that members of his own party in the Senate came up with the mechanism to pay for the bill in an effort to push it forward. "I think there's a calculation over in the Senate that robbing from poor people has no political consequences," he said.
Congress has not updated school lunch programs in five years. The reauthorization bill that passed the Senate includes many items that the first lady has championed as part of her "Let's Move" initiative to combat child obesity in the United States.
Among other things, it provides more money to poor areas to subsidize free meals and requires nutrition programs to include healthier foods. To help offset the higher cost of including more fruits and vegetables, the bill increases the reimbursement rate for school lunches.
CNN Congressional Correspondent Dana Bash contributed to this report