SDLP leader Colum Eastwood has backed party colleague Claire Hanna over a social media outburst aimed at DUP MP Ian Paisley.
Ms Hanna called the North Antrim MP a "gob****e" after seeing his response to a BBC reporter's question about whether during a visit to Downing Street he would be offering sympathy to Theresa May "after a difficult day".
Mr Paisley – who in July received an unprecedented 30-sitting day suspension from Westminster – replied: "I'll be asking her for milk and no sugar," before saying how the DUP planned to advise the British prime minister on how Brexit should be delivered.
"Northern Ireland people are very direct, very clear, and we have given the prime minister precise instructions of where we think we should be in the best interests of the nation," he said.
South Belfast MLA Ms Hanna responded to the clip by tweeting: "Take back control and hand it to this gob****e."
"It genuinely kills me that he is an elected representative, it degrades everything," she later tweeted.
The SDLP representative received hundreds of retweets and likes for the post, which she has not deleted.
She was also given the support of her party leader, who said his colleague's comments were "very restrained".
"Just catching up with 'gob****egate'," Mr Eastwood tweeted.
"I think Claire Hanna was very restrained but accurate in her use of language."
Last month it emerged that Mr Paisley was facing fresh allegations of enjoying overseas hospitality but failing to declare it to the Westminster authorities.
His suspension last year, which led to the first recall petition in parliamentary history, came after he failed to register two luxury family holidays in Sri Lanka, which were paid for by its government.
Mr Paisley also lobbied on behalf of the Sri Lankan government, in 2013 urging the then prime minister David Cameron not to support a UN probe into human rights abuses on the south Asian island.