Labour MP Ms Cooper had just finished tearing into Prime Minister Theresa May when the camera caught David Mundell shouting out in her direction .
The MP for Dumfriesshire, Clydesdale and Tweeddale, and Scottish Secretary was immediately accused of cursing at Miss Cooper.
One Twitter user wrote: “David Mundell calling Yvette Cooper a 'stupid bitch' please can this be shared. #davidmundell.”
Another said: “Tory MP shows true colours David Mundell calls Yvette Cooper a 'stupid bitch' they really don`t like the truth.”
PMQs live images Wed, April 19, 2017
Theresa May arrived in the Commons for PMQs to a roar of applause from her Conservative colleagues
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'Labour party will be going into the election pledging to spend £5billion extra’
But Mr Mundell hit out at the comments and clarified what he said on Twitter.
He wrote: “For all you Twitter lip readers out there, I said ‘Leadership Pitch’ after Yvette Copper's PMQ.”
Miss Cooper tore into Mrs May in the House of Commons.
David Mundell has been accused of calling Yvette Cooper a "bi***"
David Mundell was behind Theresa May when he was accused of swearing at Yvette Cooper
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She said: “The Prime Minister yesterday said she was calling an election because parliament was blocking Brexit.
“But three quarters of MPs and two thirds of the Lords voted for article 50. So that’s not true it it?
“And a month ago she told her official spokesman to rule out am early general election and that wasn’t true either, was it?
For all you Twitter lip readers out there, I said "Leadership Pitch" after Yvette Copper's PMQ. Don't think I was only one to think that!
— David Mundell (@DavidMundellDCT) April 19, 2017
Yvette Cooper MP has been accused of making a play for Labour leadership
“She wants us to believe she is a woman of her word. Isn’t the truth that we can’t believe a single word she says?”
But later Mr Mundell said he believed it was a bid for leadership as Jeremy Corbyn is expected to lose to Theresa May at the general election on June 8.
He added on Twitter: “Don't think I was only one to think that!”