Sean Spicer asks whether executive powers were abused in 2016, as former national intelligence director says he can deny existence of surveillance order

The White House has asked Congress to investigate Donald Trumps allegation, presented without evidence, that Barack Obama ordered illegal wiretapping of Trump Tower during the 2016 presidential election.

On Saturday, a spokesman for Obama said the former president had not ordered any such surveillance. On Sunday a former director of national intelligence, James Clapper, went further, denying the existence of any surveillance order at Trump Tower, at least during his tenure.

In his demand for an investigation, White House press secretary Sean Spicer did not provide any evidence for the presidents claims, but said reports about potentially politically motivated investigations were very troubling.

He did not specify what reports were in question, though late last week rightwing radio and news sites, including the website recently run by the presidents chief strategist, circulated the idea that Obama had tried to undermine the Trump campaign.

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