A House Ways and Means Committee markup that could decide the fate of the Sanders-Ocasio-Cortez artificial intelligence training moratorium narrowed Tuesday to a contest over three undecided committee Democrats, after a morning of closed-door whip meetings and a late-afternoon White House outreach call left both supporters and opponents of the bill describing the outcome as too close to call.

Committee staff said the markup, scheduled to begin at 10 a.m. Wednesday in the Longworth House Office Building, would open with a 30-minute manager’s amendment offered by Chairman Jason Smith, R-Mo., that does not strip the bill’s 18-month moratorium but adds a research-exemption carve-out, a one-year sunset on the per-FLOP excise study, and a state-preemption clause that two committee Democrats publicly opposed last week. Republican committee aides said the amendment was negotiated over the weekend with at least one moderate Democrat and was designed to peel off two votes; Democratic aides familiar with the talks disputed that account, saying the amendment “tightens the no votes, not the yes votes.”

The arithmetic remained tight as of Tuesday evening. The committee splits 24 Republicans to 21 Democrats, and Republican members are widely expected to vote no in a bloc. That requires Democratic Ranking Member Suzan DelBene of Washington to hold all 21 Democrats to pass the bill on a straight party-line tie that would fail under committee rules — meaning supporters need at least one Republican defection or all 21 Democrats plus a procedural maneuver that has not been publicly floated. Three Democrats — Representatives Brad Schneider of Illinois, Linda Sanchez of California and Terri Sewell of Alabama — have declined to publicly state a position, and a fourth, Representative Don Beyer of Virginia, told reporters Tuesday morning he was “still listening.”

“This is the closest committee vote I have whipped in fifteen years on this committee,” said Representative Pramila Jayapal of Washington, who is not a Ways and Means member but who chairs the Congressional Progressive Caucus and spent much of Tuesday in DelBene’s office. “Members are weighing constituent jobs against constituent power bills. That is not a vote that breaks neatly on ideology, and the lobbying has been overwhelming.”

The bill, formally the Algorithmic Energy and Labor Protection Act, cleared the Senate on April 7 by a 52-48 vote after three Republicans and two Independents joined most Democrats. It would impose an 18-month moratorium on training runs above a defined compute threshold and direct the Treasury to study a per-FLOP excise tax on frontier model training. House Ways and Means has jurisdiction because of the tax provision; if the committee approves the bill, it advances to the House Rules Committee and could reach the floor as early as next week.

The White House sharpened its posture on Tuesday. In a written statement issued shortly after 4 p.m., Press Secretary Karoline Leavitt said President Donald Trump “has serious concerns” about the bill’s competitiveness implications and would “review any legislation that reaches his desk against the standard of U.S. technological leadership.” Two senior administration officials, speaking on condition of anonymity to describe internal deliberations, said the president called at least two committee Democrats Tuesday afternoon — they declined to identify them — to argue the bill in its current form would push training infrastructure offshore.

The statement stopped short of a veto threat, a distinction that Senator Bernie Sanders, I-Vt., the bill’s lead Senate sponsor, seized on at a Senate Press Gallery briefing late Tuesday. “The White House has not said it would veto this bill. The White House has said it has concerns. Those are not the same thing,” Sanders said. “I expect the House will pass this bill in committee tomorrow, and I expect the president to sign it if it reaches his desk.” Representative Alexandria Ocasio-Cortez, D-N.Y., the bill’s House lead, did not appear at the briefing but issued a written statement saying she had spoken with all four undecided committee Democrats on Tuesday and was “encouraged by the conversations.”

Industry pressure remained intense. The Computing Infrastructure Council, the trade group representing the four largest U.S. cloud operators, told members in a Tuesday memo obtained by reporters that the chairman’s amendment did “not adequately address the bill’s core flaw” and urged a no vote on the underlying legislation regardless of which amendments are adopted. Three hyperscaler chief executives were on Capitol Hill on Tuesday for a third straight business day, according to House visitor logs, with one taking a late-afternoon meeting in DelBene’s personal office that an aide said lasted 42 minutes.

“The argument we are making is not that AI does not need rules,” said Marcus Underwood, the council’s chief executive, in a brief hallway exchange outside the Longworth building. “The argument is that a moratorium written this broadly catches a lot of useful work and freezes investment that has already moved forward. There are better instruments.”

Supporters of the bill spent Tuesday holding their own pressure events. The AFL-CIO, the Sierra Club, the Communications Workers of America and a coalition of nine state attorneys general released a joint letter Tuesday morning urging Ways and Means Democrats to vote yes, citing wage data from the council’s own filings showing roughly 1.4 million U.S. workers in occupations the moratorium’s authors classify as exposed to large-language-model automation. The Sanders office circulated grid-impact data from the Energy Information Administration showing data-center load growth on the PJM Interconnection up 19 percent year-over-year in the first quarter.

The political environment around the bill has been reshaped by the Iran ceasefire, which took effect April 15 and has begun to ease the price of crude, equities and political bandwidth in Washington. Several Democratic aides said members who had been preoccupied with war supplemental and war powers fights through the weekend were only beginning to focus on the moratorium markup Tuesday. The Senate is expected to take up a $96 billion war supplemental on Thursday, and a House Rules Committee meeting on the Kaine-Murphy war powers resolution remained tentatively scheduled for Friday.

“What you are watching this week is two debates that should have been held in different years happening in the same week,” said Maya Reinhardt, a senior fellow at the Aspen Tech Policy Hub and a former Commerce Department official. “Members are voting on the architecture of a war that just ended and on the architecture of an industry that has not yet matured. The bandwidth costs are real, and the lobbying calendars do not care.”

Chairman Smith’s office said Tuesday evening that the markup would proceed on schedule and that additional procedural details, including a final witness list and amendment schedule, would be posted on the committee’s website by 8 a.m. Wednesday.