WASHINGTON • Deadline nearing, the deficit-reduction talks in Congress sank toward gridlock Friday after supercommittee Democrats rejected a late Republican offer that included next-to-nothing in new tax revenue. Each side maneuvered to blame the other for a looming stalemate.

The panel faces a deadline of Wednesday, the day before Thanksgiving, and lawmakers on both sides stressed they were ready to meet through the weekend in a last-ditch search for compromise.

But there was little indication a breakthrough was likely in a day of closed-door meetings.

Elsewhere at the Capitol on Friday, the House rejected a Republican proposal to amend the Constitution to require a balanced budget, a proposal that would have conceded Congress was unable to fight mounting federal red ink unless its hand was forced.

In the midst of the urgent effort to accomplish that deficit-cutting goal, Republicans disclosed they had outlined an offer on Thursday for about $543 billion in spending cuts — leaving Medicare, Medicaid and Social Security untouched — and $3 billion in higher tax revenue.

Democrats have long demanded that Republicans agree to significant amounts of higher taxes on the wealthy as part of any deal, and they quickly rejected the offer, according to officials in both parties.

"Where the divide is right now is over taxes, and whether the wealthiest Americans should share in the sacrifices," said Washington Sen. Patty Murray, the Democratic co-chair of the panel.

One Republican leadership aide familiar with the offer said it included only provisions that had drawn bipartisan support in talks throughout the year. This aide also noted it included President Barack Obama's proposal to reduce the tax break used by purchasers of corporate jets.

It was unclear where the talks would turn next, but the GOP proposal suggested the discussions had in effect moved into a range of savings far below the $1.2 trillion the committee has been seeking.

It also appeared Republicans were jettisoning a plan for $300 billion in higher tax revenue, an offer that had exposed internal GOP divisions when it was presented two weeks ago. It also has failed to generate momentum for a compromise among Democrats.

If the panel fails to reach agreement, $1.2 trillion in automatic spending cuts are to take effect beginning in 2013, a prospect that lawmakers in both parties say they want to avoid.