For years, federal spending on the military and veterans affairs seemed nearly as sacrosanct as Social Security. But with some House Republicans now talking about cutting the Pentagon budget, veterans groups have grown nervous that the Department of Veterans Affairs will be next. And so today, a number of groups took preemptive action, vigorously blasting a proposal for V.A. budget cuts that came from a Tea Party leader, Representative Michele Bachmann, Republican of Minnesota.

The veterans groups were responding to a plan recently posted on Representative Bachmann’s congressional Web site to cut federal spending by $400 billion. The plan calls for deep cuts to just about every federal agency, and veterans affairs is not spared: She proposed lopping $4.5 billion from its annual $125 billion budget, including by capping increases to health care spending for veterans and reducing some disability compensation.

The first group to respond was Veterans for Common Sense. In a message to its membership this week, the group called the proposal “outrageous” because 10,000 new veterans from Iraq and Afghanistan are flowing into the veterans health system each month.

“You can’t cut when demand is rising,” said Paul Sullivan, the group’s executive director.

The Veterans of Foreign Wars, the oldest and largest of the groups, followed soon after, releasing a statement from its national commander, Richard L. Eubank, saying: “No way, no how, will we let this proposal get any traction in Congress.”

Paul Rieckhoff, executive director of Iraq and Afghanistan Veterans of America, posted an Army Times article about the brouhaha on his Facebook page under the words, “Oh hell no!”

Before the day was over, groups like the American Legion, Disabled American Veterans and AMVETS also chimed in.

In a statement in the Saint Cloud Times, the congresswoman, who founded the Tea Party caucus in Congress and is considering running for president, said the proposal was intended to generate discussion. “Instead of making it easier for Washington to spend more of your tax dollars, I’m calling for Congress to do the hard work of making real and necessary cuts in federal spending,” she said.

Veterans groups had been bracing for a fight over budget cuts to veterans affairs and are expecting more to come. Some House Republicans have also proposed privatizing some veterans services, an idea many groups are likely to oppose.

Though the veterans groups are nonpartisan, their membership is widely thought to be heavily Republican, and so the fierce attack on a Republican presidential hopeful was not inconsequential. Not surprisingly, Democrats piled on.

“We have to have an aggressive, long-term plan to tackle our nation’s debt, but attempting to balance the budget on the backs of veterans who have risked life and limb in service of our country is unacceptable,” said Representative Tim Waltz, a Democrat from Minnesota and a veteran himself.