With the crisis chatter in Washington now turning to speculation about the coming budget talks and the possibility of a “grand bargain” to replace the sequester, liberals and unions are getting increasingly nervous that Congressional Dems will give up entitlement benefits cuts in exchange for, well, whatever is on offer from Republicans, which isn’t at all clear.

In an interview, Damon Silvers, the policy director of the AFL-CIO, laid down a hard line, putting Dems on notice that any agreement that cuts entitlement benefits — even in a deal that includes GOP concessions on tax hikes — is a nonstarter. Silvers strongly suggested labor would withhold support in 2014 from any Dem lawmaker who supports such a deal.

“We are opposed to Social Security, Medicare, and Medicaid benefits cuts. Period,” Silvers told me. “There will be no cover for members of either party who vote for such a thing.”

Silvers said the AFL-CIO also opposes the entitlements cuts in the President’s budget, such as Chained CPI and a form of Medicare means testing. It’s unclear how, or whether, those will figure in what Dems bring to the table in the budget talks, which are mandated by the deal just reached to end the crisis.

“Chained CPI is like the vampire of American politics,” Silvers said. “It keeps being shot through the heart and it keeps reviving. The reason it keeps coming back is because it has billionaires behind it.”

Silvers was referring to individuals and groups like Pete Peterson, a Wall Street billionaire whose lavishly-funded foundation has been pushing for cuts to these programs for years, Fix the Debt, which is pushing for deficit reduction, and GOP-aligned groups that have in recent years promoted the Paul Ryan budget. All of these are expected to spring into action when this fall’s fiscal fight — and talk of a “grand bargain” — heats up.

Silvers characterized the posture of those groups as follows: “Now that the last round of insanity is over, time to attack the social insurance system.”

“Cutting Social Security and Medicare and Medicaid benefits is not a route to a grand bargain; it is a route to deadlock,” Silvers continued. “We and a lot of folks are going to oppose it categorically, and everything will grind to a halt.”

Pressed on whether the AFL-CIO would support primary challengers to any Dems who support benefits cuts, Silvers demurred, but he said that all of the material created in such a battle — video, ads, etc. — would be available to any primary challenger, and added: “That’s the minimum we’re going to do. It only gets worse from there.”

In an interview with the Huffington Post, Harry Reid said Dems would not agree to any deal in the budget talks that simply trades entitlement cuts for relief to the sequester. That suggests Dems think they are in a strong political position heading into the budget talks, and that they want to lay down a hard marker in response to Republicans who have already ruled out agreeing to new revenues.

But that doesn’t preclude the sort of “grand bargain” that might include entitlement benefits cuts and the closing of loopholes on the rich and corporations. Even this is a non-starter for labor unions and liberal groups, who believe that despite yesterday’s big victory, Dems must continue to resist allowing the looming political battle to get pulled on to GOP turf, where we’d be debating still more spending cuts — including to social insurance system benefits — at a time when austerity is already crippling the recovery.