DUP MP Gregory Campbell has called on Labour leader Jeremy Corbyn to apologise to Troubles victims after he failed to meet with them during this week's trip to Northern Ireland.
Mr Campbell had invited Mr Corbyn to meet with victims during his visit.
He described the Labour leader's "snub" as a demonstration of "basic bad-manners and disrespect".
The East Londonderry representative said Mr Corbyn's office had apologised for how the invitation was handled.
Mr Campbell called for the Opposition leader to apologise to the victims, who live on, or close to the border.
Mr Corbyn visited Belfast on Thursday and Derry, Strabane and the Irish border on Friday.
He has denied snubbing victims of the IRA.
Mr Corbyn said he was only notified of the invitation on Wednesday, when his schedule had already been agreed.
He said shadow Northern Ireland secretary Tony Lloyd would be happy to meet victims' groups.
"It is absolutely not a snub," said Mr Corbyn.
"I did receive a letter from Gregory Campbell yesterday. We had already made the arrangements for this visit.
"Tony Lloyd, our shadow Northern Ireland secretary, will be meeting them."
Mr Campbell said Mr Corbyn had behaved disrespectfully.
“It took 10 days for Mr Corbyn's office to even acknowledge my invitation to meet victims of terror. Even at that stage it was only an acknowledgement and no commitment to either accept or decline. This is not only disappointing but it is downright disrespectful and basic bad-manners," the East Londonderry MP said.
"These victims have employment. As soon as they heard he was coming to the border locality they indicated that they would like to meet with him. They needed sufficient notice to inform their employers and ensure arrangements could be made. The uncertainty continued for ten days.
"Whilst Mr Corbyn’s office have apologised to me for how this invitation has been handled, actions speak louder than words."
The Belfast Telegraph has contacted The Labour Party for a response to Mr Campbell's comments.