Both the chairman and ranking minority member of the House Intelligence Committee have asked President Trump to produce evidence that Trump Tower phones had been wiretapped by the Obama administration no later than today.

The request came in a letter to the White House by Republican chairman Devin Nunes and Democrat Rep. Adam Schiff.

President Trump has requested that Congress investigate the wiretapping as part of its probe into Russian hacking of the election.

The Hill:

A congressional aide confirmed to The Hill that Schiff and Nunes made the request in a letter to the White House. The letter was first reported by The Associated Press.

Trump has kept his distance from the press since last weekend, when he accused former President Barack Obama of wiretapping Trump Tower before the November election.

Trump did not provide any evidence of the claim, and a spokesperson for Obama denied that he or any White House official called for the surveillance.

The White House has asked that an investigation of the alleged wiretaps be part of the probe into Russia's interference in the presidential election.

Nunes has said that the intelligence panel would investigate potential surveillance of political parties as part of its Russia inquiry.

Democrats have slammed Trump for the accusations, with Schiff calling them "outlandish" and destructive."

If there are any ongoing inquiries resulting from wiretaps authorized by a secret FISA warrant, President Trump may be unable to comply with that request – not without blowing up the investigation. 

But it is more likely that if any surveillance of Trump campaign aides occurred, no warrant would have been issued at all.  NSA intercepts of communications originating in Trump Tower could have been accessed under certain circumstances by other intelligence agencies.  If that were the case, any evidence would be anecdotal.  It's hard to see Nunes and Schiff accepting that as proof. 

Trump may be unable to respond to the intel committee request because there is no paper trail that investigators could examine.  Unless there are warrants issued by the Justice Department of which no one is aware, it is likely that the intel committee's demand that Trump put up or shut up about wiretapping will go unheeded.