During a brief visit to Belfast on Saturday, BNP leader Nick Griffin angered many by posting a highly inflammatory tweet.
According to Joe.ie, Griffin was trying to drum up support for his party in Belfast, where tens of thousands of people were commemorating the 100th anniversary of the signing of the Ulster Covenant.
In a tweet posted later that evening he said: "So Ulster pics have upset my Republican stalkers. Tell you what the bodran can't match the lambeg, you Fenian bastards."
According to the BBC, Griffin said he used the word Fenian in a tweet after receiving abusive messages from republicans and that the remark was not aimed at Catholics in general. He said he would not be withdrawing his remark.
"I knew this was going to be a big and spectacular parade. I wanted to come along and have a look," said Mr Griffin.
"It wasn't about Catholics, it was about the operatives of the republican grievance exploitation machine who were leaving foul-mouthed tweets on my Twitter feed. It was about them specifically. They're the ones I had a go at.
"If they want to leave vast amounts of foul-mouthed abuse on my Twitter feed when I'm showing people on the mainland, primarily, a part of the culture of Britain that they don't see much of, and if that upset a group of republicans, I'm not going to apologise."