By Eugene Scott

CNN

(CNN) -- The investigation into President Donald Trump's unverified allegations that former President Barack Obama had Trump Tower wiretapped will be public, the leading Democrat on the House Intelligence Committee vowed Thursday.

"I think what (White House press secretary) Sean Spicer and the President wanted was to take this spurious claim and try to bury it in a closed hearing in the intelligence committee. We're not going to allow that to happen. We're going to air this very publicly," Rep. Adam Schiff told CNN's Chris Cuomo on "New Day."

The Trump administration has so far declined to provide any information about the President's allegations since he tweeted them Saturday. Obama's former aides have emphatically denied Trump's claims, and sources told CNN Obama himself was exasperated after learning of the accusations.

"Nothing has changed," Spicer told CNN's Jim Acosta Wednesday when asked whether there was new evidence to support the claims. "It's not a question of new proof or less proof or whatever. The answer is the same, which is that, I think, there was a concern about what happened in the 2016 election."

The White House spokesman said the intelligence committees have the capabilities to look into the issue objectively.

Schiff said Trump will be "exposed" publicly if an investigation reveals that there is no merit to his claims. The intelligence committee already planned to investigate the relationship between Trump associates and Russian officials during the 2016 election.

"If the President is going to make outlandish claims like this in the future, he needs to know he will be exposed and high-ranking people within the US government -- like the director of our intelligence agencies and the FBI -- will be forced to say the President wasn't telling the truth," the California Democrat said.

Trump making accusations without providing evidence is harmful to democracy and will continue if he is not challenged, Schiff said.

"If we don't confront him on this, you can expect he's going to make other equally false claims in the future and this is not only hurting him but it's hurting the presidency," he said. "It's hurting our credibility around the world."

"I think there are profound questions about whether this President is capable of growing with the job," Schiff added.