The clock is ticking.
The top lawmakers on the House Intelligence Committee have asked the Justice Department to turn over by Monday any evidence showing Trump Tower was wiretapped during the 2016 presidential race — an explosive accusation President Trump leveled at former President Obama without providing proof.
The request came in a letter sent last week to the acting deputy attorney general by the committee chairman, Devin Nunes (R-Calif.), and its ranking Democrat, Adam Schiff (D-Calif.), congressional aides told NBC News. FBI chief James Comey, who reportedly asked the Justice Department to publicly reject Trump's claim, was also sent a copy of the letter.
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Nunes has promised his panel would look into potential surveillance of political parties as part of its broader investigation of Russian meddling in the election.
Trump did not offer evidence to support his infamous March 4 tweets, in which he compared the alleged wiretapping to the Watergate scandal and called Obama a "bad (or sick) guy." Kevin Lewis, a spokesman for Obama, said "any suggestion" that the former president ordered surveillance on Trump was "simply false."
Democrats have criticized Trump for his unsubstantiated claims, and several congressional Republicans have been leery of them.
In an interview on Sunday, Sen. John McCain (R-Ariz.), the chairman of the Armed Services Committee, implored Trump to show his cards.
"The president has one of two choices — either retract or provide the information that the American people deserve," McCain said in an interview on CNN's "State of the Union." "I have no reason to believe that the charge is true, but I also believe that the president of the United States could clear this up in a minute."
In an interview with CBS' "Face the Nation" broadcast Sunday, House Speaker Paul Ryan said he had not seen anything suggesting Obama wiretapped Trump, joking that Trump's wiretapping tweet storm "wasn't really part of the health care marketing campaign."