WASHINGTON — As President Trump refuses to allow President-elect Joe Biden to receive intelligence briefings — even those he was getting during the campaign — an increasing number of Trump’s allies are calling for Biden to have access to the information.

“I just don’t know of any justification for withholding the briefing,” Texas Sen. John Cornyn, a member of the Senate intelligence committee, said Thursday.

“I see no problem with that,” said Iowa Sen. Chuck Grassley, the Republican Party’s longest-serving senator.

“I think so, yes,” said Senate Judiciary Committee Chairman Lindsey Graham, one of Trump’s closest confidants, when asked if Biden should be briefed.

The Senate Republicans advocated for Biden to receive the classified national security information even as they refused to acknowledge that the Democrat has won the presidential election, citing Trump’s baseless claims of fraudulent votes.

“At this point at least, I think he should absolutely be getting intelligence briefings,” Missouri Sen. Josh Hawley said of Biden. “The briefings he’s been getting as a candidate should continue. I think he should continue to get what he’s been getting and then let’s get on with the resolutions on some of these disputes.”

The GOP pile-on supporting the intelligence briefings amounted to miniscule cracks in support for Trump as he refuses to concede the race, but was also in line with Republicans’ occasional, carefully worded answers about his actions during his presidency. While only a handful of Republicans have called Biden the president-elect, most were comfortable Thursday challenging the Trump administration on withholding intelligence information, which could constitute a national security risk when Biden assumes office.

“Both sides need to have access to the information because we don’t know who the president is going to be, so allow that part of this process to still continue just for the sake of national security,” said Sen. James Lankford, echoing Trump’s unsubstantiated claims of voting problems.

Lankford said he would pressure Trump administration bureaucrats to move ahead with the process of transition so Biden could be read in on classified matters. He said Wednesday that he would “get involved” if that didn’t move forward.

For now, the office of National Intelligence Director John Ratcliffe, a loyal ally to Trump, says it can’t begin talking with the Biden transition team until the government starts that transition process. But the Trump administration is delaying it.

Ratcliffe’s office, which oversees more than a dozen U.S. intelligence agencies, said it must follow the Presidential Transition Act, which requires the General Services Administration to first ascertain the winner of the election, which Trump is contesting without evidence. GSA administrator Emily Murphy, who was appointed by Trump, has not yet officially designated Biden as the president-elect.

Intelligence agencies have given generalized intelligence briefings — minus information on covert operations and sources and methods — for presidential nominees since 1952. President Harry S. Truman authorized them for both parties’ candidates because he was upset about not learning about the U.S. effort to develop an atomic bomb until 12 days into his presidency.

Biden was receiving those briefings, along with counterintelligence briefings, but is no longer getting that information, according to a person familiar with the process who was not authorized to discuss it publicly. A spokesman for Biden’s transition team declined to comment.

Biden has played down the significance of the delay in getting access to the intelligence.

“Look, access to classified information is useful. But I’m not in a position to make any decisions on those issues anyway,” Biden said Tuesday. “As I said, one president at a time. He will be president until Jan. 20. It would be nice to have it, but it’s not critical.”

Biden is familiar with the President’s Daily Brief, having read the most sensitive intelligence document prepared for U.S. officials during his eight years as vice president. But threats are ever-changing and as Inauguration Day nears, his need for Trump to let him get eyes on the classified information will become more critical.

National security and intelligence experts say they hope Trump changes his mind, citing the need for an incoming president to be fully prepared to confront any national security issues on Day One.

U.S. adversaries can take advantage of the country during an American presidential transition, and key foreign issues will be bearing down on Biden the moment he steps into the Oval Office in January.

For example, unless Trump extends or negotiates a new nuclear arms accord with Russia before Inauguration Day, Biden will have only 16 days to act before the expiration of the last remaining treaty reining in the world’s two largest nuclear arsenals. Perhaps U.S. spies have picked up tidbits about the Russians’ red lines in the negotiations or about weapons it really wants to keep out of the treaty.

That’s the type of information that might be in the daily summary of high-level, classified information and analysis on national security issues that’s been offered to presidents since 1946.

Having access to it also could help Biden craft a possible response to North Korea, which has a history of firing off missiles or conducting nuclear tests shortly before or after a new president takes office.

Biden, a former vice president, has decades of experience in foreign affairs and national security. But he probably has not been privy to the latest details about how Iran is back to enriching uranium or the active cyber attack operations of Russia, China and Iran. China’s crackdown on Hong Kong is heating up. The threat from Islamic extremists, although curbed, still remains.

The 9/11 Commission Report on the Sept. 11, 2001, attacks warns of the danger in slow-walking presidential transition work in general, not just the intelligence piece. The George W. Bush administration didn’t have its deputy Cabinet officers in place until the spring of 2001 and critical subcabinet positions were not confirmed until that summer — if then, the report said.

“President-elect Joe Biden and his transition team should not suffer a similar delay,” John Podesta, who served as White House chief of staff under Clinton, and Bush’s chief of staff Andrew Card wrote this week in The Washington Post. “We have since learned the serious costs of a delayed transition.”