Transition officials for President-elect Joe Biden called on a top Trump administration appointee Monday to end what they said was unwarranted obstruction of the money and access that federal law says must flow to the winner of a presidential election.

The officials, speaking on background to reporters Monday night, said it was nearly unprecedented for Emily W. Murphy, the administrator of the General Services Administration, to refuse to issue a letter of “ascertainment,” which allows Biden’s transition team to begin the transfer of power.

By law, Murphy, the head of the sprawling agency that keeps the federal government functioning, must formally recognize Biden as the incoming president for his transition to begin. It has been three days since news organizations projected that he was the winner of the election, and Murphy has still not acted.

The transition officials said her inaction was preventing Biden’s teams from moving into government offices, including secure facilities where they can discuss classified information. The teams cannot meet with their counterparts in agencies or begin background checks of top Cabinet nominees that require top-secret access.

A White House official pointed out, as several Trump allies have, that the transition after the 2000 presidential election was delayed by the court fight between the campaigns of Vice President Al Gore and Gov. George W. Bush of Texas over several weeks. The official said it would be strange for President Donald Trump to send some kind of a signal to allow the transition to start while he is still engaged in court fights.

But Biden’s aides said that the dispute in 2000 involved one state with only about 500 ballots separating the winner and loser, far less than in the current contest. In every other presidential race for the past 60 years, the determination of a winner was made within 24 hours, they said — even as legal challenges and recounts continued for weeks.

They said that they were considering “all options,” including potential legal action, to push Murphy to let the transition begin.

Murphy, a Trump administration appointee who described herself as “a bit of a wonk” at her Senate confirmation hearing in October 2017, and also said that she was “not here to garner headlines or make a name for myself,” so far has chosen to side with the White House and Trump, standing between Biden’s team and a smooth transition.

The president refuses to concede the election and has his campaign contesting results in multiple states. Most Republicans have declined to recognize Biden, much less appointees like Murphy. And so the transfer of power that must take place is in limbo.

A White House spokesperson did not immediately respond to a question about whether Trump was willing to let Murphy begin the transition without a concession from the president, as his court fights play out.

Leslie Dach, who was to lead the transition for the Department of Health and Human Services had Hillary Clinton won the presidency in 2016, said that despite the advance work done by Biden’s team during the campaign, nothing could supplant having direct access to agencies, and that is impossible without Murphy.

“I think this is Trump sending a clear signal to everybody still standing in the administration that you’ve got to still follow his grievances,” Dach said.

The stalling of the transition is part of an overarching refusal to acknowledge the election results by the Trump administration.

Officials in the White House presidential personnel office, known as PPO, have signaled that they will fire political appointees who search for new jobs outside of the administration during this time, according to two people briefed on the internal discussions. And on a call with USAID staff members Monday, officials described the election as still happening, according to a recording obtained by Axios.

In a letter Sunday from the nonpartisan Center for Presidential Transition, veterans of previous administrations warned, “While there will be legal disputes requiring adjudication, the outcome is sufficiently clear that the transition process must now begin.”

Aides to Biden have been working for months to develop fine-tuned transition plans to help the president-elect quickly make good on his campaign promises. Those review teams made up of people knowledgeable about each federal agency are critical.

Murphy has the legal authority to “turn on” the transition, releasing the $6.3 million in federal funds budgeted for the effort, making office space available and empowering team members to visit agency offices and request information.

Aides to Biden said that they expected Murphy to act within a few days, but that they were bracing for the possibility that political pressure from the president and his Republican allies would prevent that. In a statement on Twitter on Sunday, Jen Psaki, a transition official, gently prodded Murphy to make the announcement.

“Now that the election has been independently called for Joe Biden, we look forward to the GSA Administrator quickly ascertaining Joe Biden and Kamala Harris as the President-elect and Vice President-elect,” Psaki wrote. “America’s national security and economic interests depend on the federal government signaling clearly and swiftly that the United States government will respect the will of the American people and engage in a smooth and peaceful transfer of power.”

Biden’s transition officials were more pointed Monday night, effectively saying that the Trump administration was reneging on promises made over the past six months to ensure a proper transfer of power if Biden won.

The officials said that they signed three separate memorandums of agreement — including one signed by Mark Meadows, the White House chief of staff — that laid out the access and money Biden’s team would receive in the days after the election. None of that has been allowed to proceed, they said.

The coronavirus pandemic has made office space less critical for the Biden transition team, which has been mostly meeting remotely for the past several months and will continue to do so, according to a transition official. There is a skeleton staff at the office space that was provided by the government before the election.

But once Murphy signals that the transition can begin, that office space will be expanded and equipped with computer systems that give the new administration access to classified systems and information, in addition to a secure location to have secret conversations.

If that does not happen in the coming days, the Biden administration has other options. Transition officials have private office space they can continue to use, and Biden and his team will continue to operate remotely. When the president-elect met with his pandemic advisory board Monday, he was in Delaware and the board members were on a big screen, calling in from their homes or offices.

The bigger issue would be access to the agencies and the information they need to begin carrying out Biden’s agenda. But people familiar with Biden’s transition said there was a partial workaround: Many of the people still working in the federal agencies were close to Biden’s advisers and might be willing to work with them to provide the unclassified information they need.

But that would not solve the problem of gaining access to classified information, which could affect the ability of Biden’s national security team to prepare itself for emergencies that it may have to confront once in office. Transition officials said one specific limitation at the moment is that Biden does not have access to a secure State Department facility that is normally used to route calls from foreign leaders hoping to congratulate the newly elected president.

Biden has been making those calls, but has not been allowed to use the State Department as has been the practice after previous elections.

Trump and his allies have criticized Democrats and the news media for projecting Biden as the winner before legal challenges and recounts have been completed. But historically, the “ascertainment” decision by the GSA administrator has not waited for the outcomes of such challenges.

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