Pete Wishart, who heads up Westminster’s Scottish Affairs committee, has since deleted the tweet which was issued on Friday morning containing the comments.
It shows a mock ballot paper for next month’s council elections. SNP and other pro-independence candidates labelled as “good guys” while pro-union candidates are branded “w**k” “w**ker” and “absolute total w**ks.” in an apparent reference to the BBC sketch show Chewn’ the Fat.
It came after First Minister Nicola Sturgeon this week called for more “courtesy and respect” in the debate over Scotland’s future.
Mr Wishart’s comments prompted an angry response from Conservative MSP Murdo Fraser.
“At the start of this week, Nicola Sturgeon pledged her party would treat opponents with respect,” Mr Fraser said.
“At the end of it, one of her MPs is issuing foul-mouthed tweets and treating it like a joke.
“For a serving MP to be indulging in low-grade insults such as this is frankly staggering. If Nicola Sturgeon is going to be true to her word, she should consider removing the SNP whip from Mr Wishart immediately.
“If not we will know her words this week meant absolutely nothing.”
Wishart previously came under fire from political opponents six months ago amid claims he used Twitter to mock the elderly, when he referred to Blairites in the Labour party as “ an embarrassing incontinent old relative who you might go and visit occasionally.”
A SNP spokesman said of the latest row: “Despite political differences, those from all sides of the debate should seek to make their case with courtesy, understanding and respect.”