A former Sinn Fein mayor found it "totally ridiculous" that Jeremy Corbyn would consider ringing him in a bid to silence his Labour MP son.
South Armagh-born MP Conor McGinn yesterday claimed that the under-pressure Labour leader planned to call his ex-councillor father after he criticised Mr Corbyn in a magazine interview.
Mr McGinn (31) is Labour MP for St Helens in Merseyside, while his father Pat is a former Sinn Féin mayor of Newry and Armagh.
He went public with his allegation after watching Mr Corbyn on television this week speaking about "kinder, gentler politics".
Mr McGinn said he could no longer tolerate the Labour leader's "hypocrisy".
"I knew for a fact that he had proposed using my family against me in an attempt to bully me into submission because he didn't like something I said," the Camlough-born MP said.
Mr Corbyn has never met or spoken to Pat McGinn.
"I can only presume that because of the much-publicised fact that my father was a Sinn Féin councillor, Jeremy felt that they would share a political affinity and was proposing to use that to ask my father to apply pressure on me," his son said.
Labour officials have said Mr McGinn's claim is "untrue" but the MP is standing by the allegation.
The Irish News last night spoke to a close friend of the McGinn family, who had been in touch with the former Sinn Féin councillor after the controversy broke.
"Anybody who knows the McGinn family knows Pat is very proud of Conor and that they remain very close," the friend said.
"He found the whole notion of Corbyn phoning him totally ridiculous. As if Pat is going to criticise his son to save Jeremy Corbyn's face? They would laugh about it were it not so sinister."
Mr McGinn is a former adviser to Vernon Coaker, who resigned from the shadow cabinet last month in protest at Mr Corbyn's leadership.
He was elected as an MP in the safe Labour seat of St Helens last year.
