The White House has determined that it will most likely have to allow the whistle-blower who filed an explosive complaint about President Trump to meet with congressional investigators, two people briefed on the matter said Tuesday.

The meeting could give Democrats a stream of evidence as they consider whether to impeach the president. Such a meeting would allow the whistle-blower to share at least some details of the complaint he filed — which relates to Mr. Trump’s efforts to get the Ukrainian government to investigate former Vice President Joseph R. Biden Jr. and his son — even if the actual document is not handed over to Congress…

The appearance that they were stonewalling Congress, in their view, could prove more damaging than the whistle-blower’s account. Mr. Trump also believes that the allegations about him are not nearly as damning as they have been portrayed and that disclosing them will undercut the impeachment drive, people close to the president said.

Inside the White House, recriminations have begun over how the situation devolved to a point where a formal impeachment inquiry has been announced, people briefed on the situation said.