With 19 days to go, the sequester standoff hardened Sunday. Congressional leaders from both parties said the deep automatic spending cuts must be prevented from taking effect, but Republicans drew a line in the sand against making tax increases part of any stopgap alternative, and Democrats did the same in vowing to protect entitlements and social programs.

President Barack Obama last week asked Congress to come up with a package of both new revenue and additional spending cuts — he did not make any other suggestions about specifics — before March 1, after which automatic spending cuts of about $85 billion over the next seven months must start to be implemented.

“We can’t be raising taxes every three months in this town,” House Majority Leader Eric Cantor, R-Va., said on NBC’s “Meet the Press.” “We want tax reform, but we want to plug those loopholes that the president talks about to bring down tax rates because we believe that’s pro-growth and we can get the economy growing again. Let people who earn the money keep more of it. The president is not talking about that. What he’s talking about is trying to raise more taxes for Washington to spend the money.”

Oklahoma Rep. Tom Cole, who was among the first Republicans to publicly break with his leadership at the end of last year and endorse higher taxes as part of a deal to avert the fiscal cliff, said on ABC’s “This Week” that he would “absolutely not” do so again because the December agreement was essentially all about revenue and so the next bill to trim the deficit needs to be entirely spending cuts.

Some of the most fiscally conservative Republicans have said they are content to have those across-the-board cuts take effect and are willing to accept such an indiscriminate approach (including an 8 percent cut in defense spending) because it would at least guarantee a decent bite into the size of government. On CNN’s “State of the Union,” Sen. Rand Paul, R-Ky., said sequestration would be a mere “pittance” toward the kind of cutbacks that are necessary. But Cantor said he didn’t want to “live with” sequestration.

House Minority Leader Nancy Pelosi, D-Calif., rebutted the GOP at every turn on “Fox News Sunday.” She said Democrats would not favor raising new taxes as part of an interim budget deal but instead will propose cutting tax breaks for oil companies and closing other such “loopholes.” She said it was a myth that Washington has a “spending problem,” the current mantra of the Republican leadership, in light of the $1.6 trillion in spending reductions mandated by the 2011 measure enacted to avert the debt limit standoff. And she said her caucus would oppose two of the biggest money-savers on the GOP agenda — raising the eligibility age for Medicare from 65 to 67 or cutting benefits for recipients.

Senate Majority Whip Richard J. Durbin, D-Ill., echoed many of those same themes on NBC’s “Meet the Press.” He said it would be wrong to cut Head Start, psychological counseling for members of the military and other programs that would be reduced indiscriminately by sequestration. “Let’s do this in a thoughtful manner. Let’s include revenue,” he said, but in a way that “doesn’t impose a tax burden on middle-class families.”