President Donald Trump on Sunday called for a congressional investigation into whether former President Barack Obama overstepped his authority investigating Russia’s involvement in the 2016 election, doubling down on claims from Saturday for which he did not provide supporting evidence.

“Reports concerning potentially politically motivated investigations immediately ahead of the 2016 election are very troubling,” White House press secretary Sean Spicer said in a statement.

“President Donald J. Trump is requesting that as part of their investigation into Russian activity, the congressional intelligence committees exercise their oversight authority to determine whether executive branch investigative powers were abused in 2016. Neither the White House nor the President will comment further until such oversight is conducted.”

The statement comes a day after Trump alleged without evidence that Obama ordered the wiretapping of phones in Trump Tower weeks before the election.

Obama spokesman Kevin Lewis on Saturday denied the former White House interfered in the investigation into the 2016 election. 

“A cardinal rule of the Obama administration was that no White House official ever interfered with any independent investigation led by the Department of Justice. As part of that practice, neither President Obama nor any White House official ever ordered surveillance on any US citizen. Any suggestion otherwise is simply false,” Lewis said.

Though neither Trump nor Spicer cited any direct evidence, both appeared to refer to recent reports on Breitbart and conservative talk radio suggesting that Obama bugged Trump’s phones. There is no public evidence to back up those assertions.

Trump’s claims on Saturday drew ire from many Democratic lawmakers, while most Republicans largely avoided commenting on the allegations publicly.

When confronted about Trump’s allegation, many congressional Republicans deferred to the president.

“I’ve never heard that allegation made before by anybody. I’ve never seen anything about that anywhere before,” Sen. Marco Rubio said on “Meet The Press” on Sunday. “The president put that out there, and now the White House will have to answer as to exactly what he was referring to.”

Trump’s allegations came on the heels of growing evidence that top officials in his campaign regularly interacted with Russian government officials, raising further questions about his and his associates’ ties to Russia.

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