Congress is warning President Obama that it will reject any deal with Iran that allows Tehran to keep the capability to develop a nuclear weapon or attempts to lift sanctions without the approval of lawmakers.

The bipartisan pressure on the president is intense as negotiators race to replace a year-old interim agreement by Monday’s deadline.

“Congress will not be satisfied with a bad deal,” Rep. Ted Deutch, D-Fla., ranking Democrat on the House Foreign Affairs Middle East and North Africa subcommittee, declared Thursday, adding that it would be unwise for the administration to try to bypass lawmakers on sanctions against Iran.

“The notion that sanctions can be lifted entirely without first coming back to Congress, after Congress has imposed those sanctions to begin with, is one that will be hard to pass muster here on the Hill.”

Republicans took an even harder line, with 43 of the 45 current GOP senators — including incoming Majority Leader Mitch McConnell of Kentucky — warning in a letter sent Wednesday to Obama that “unless the White House genuinely engages with Congress, we see no way that any agreement consisting of your administration’s current proposals to Iran will endure in the 114th Congress and after your presidential term ends.”

Their warning was backed up by the 11 Republicans newly elected to the Senate earlier this month, who said in a joint statement Friday that “if the Obama administration reaches a deal that we deem unacceptable, we will join our colleagues in the Senate to act to keep America safe.”

Obama has risked a lot to keep the talks going on limiting Iran’s nuclear program and so far has been unwilling to walk away even as Tehran’s negotiating posture hardens. But with Republicans taking control of the Senate in January and many Democrats sharing their concern that he has made too many concessions, his time may be running out.

Officials and experts are skeptical that a deal can be reached by the deadline, and both Iranian and U.S. officials discounted for now the possibility of seeking an extension of the talks.

“We’re going to race against the clock to get this done,” White House spokesman Eric Schultz said Friday when asked about a possible extension.

Iranian Foreign Minister Mohammad Javad Zarif said negotiators from the P5+1 — the United States, Britain, France, Russia, China plus Germany — had brought no new proposals to the table, and sources close to the Iranian negotiating team told state-owned PressTV that the main stumbling block was the removal of sanctions, not the number of centrifuges used to enrich uranium or the size of Iran’s uranium stockpile.

Negotiators already have been willing to allow Iran to retain some centrifuges and continue to enrich uranium, with Secretary of State John Kerry saying last month that the goal was to close off Tehran’s pathways to a nuclear bomb sufficiently to allow at least a year’s warning if the Iranians try to cheat.

But that position has raised concerns among lawmakers, especially in light of an International Atomic Energy Agency report earlier this month that said Iran was not providing enough information to address suspicions that it may have conducted research into developing a nuclear weapon.

Experts say Iran must come clean with the IAEA about its past activities for any deal to meet the standards set by the administration and by the United Nations Security Council.

“These transparency mechanisms need to be legally binding,” Olli Heinonen, a former deputy director of the U.N. agency, told reporters in a conference call last week.

McConnell has promised a vote in the new Congress on legislation to toughen sanctions, a bill that was bottled up by outgoing Senate Majority Leader Harry Reid, D-Nev.

Several Democrats warned this week they would back the move if any deal is not to their liking.

“Unless Iran is willing to agree to a final deal that prevents it from building, developing or acquiring a nuclear weapon, we should not allow any relaxation of sanctions,” Sen. Charles Schumer, D-N.Y., said Friday. “Iran must dismantle their nuclear infrastructure, limit their nuclear research, and agree to inspections anywhere, and at any time, for decades to come. Only after complete verification of Iran’s compliance should the U.S. consider a gradual relaxation of sanctions.”