A UKIP donor has said he "sticks by" a tweet he was "sick to death" of hearing about the Hillsborough disaster.
Arron Banks posted the remarks last week after UKIP chief Paul Nuttall apologised for false claims he lost close friends in the 1989 tragedy.
He told BBC Radio 5 live: "I know the people up in Liverpool probably get hot under the collar for those comments, but... I stick by what I said."
He also accused Labour of "politicising" the disaster.
The Labour Party is yet to respond.
Ninety-six people died after a crush at an FA Cup game between Liverpool and Nottingham Forest at Sheffield Wednesday's ground.
Mr Banks described the backlash to his comments and the reaction to the false claims on Mr Nuttall's website as a "Labour smear campaign".
He said: "Yes, I am sick to death of hearing about Hillsborough. The politicisation of it by the Labour party is atrocious."
He continued: "I mean, Hillsborough obviously was a disaster, it was wrong, it was covered up... the Labour party want to politicise it as an issue, but I find that deeply distasteful."
On Saturday, Labour MP Andy Burnham, who was involved in the Hillsborough justice campaign, tweeted: "We set up an All-Party Group to provide cross-party support for the Hillsborough families & take the issue beyond party politics."
In a radio interview last week, Mr Nuttall said he knew people who died in the disaster, but he was "appalled" his website had given the impression that he was close to any of the victims
He said he did not check press releases posted by an aide in 2011 and 2012.
Mr Banks said: "It had been on his website since 2011. You know what happens in politics. The Labour Party goes through whatever anyone's ever said and then brings it up in the last week of a by-election."
Mr Nuttall, who is an MEP for North West England, is a candidate in Thursday's Stoke Central by-election.
He has been joined in his election campaign by Kieran Aspden, chairman of UKIP Preston, who said his father spent three days in a coma after being in the crush at Hillsborough.
Mr Aspden said Mr Nuttall has handled the backlash over Hillsborough "professionally" and was "fully behind" him.
Earlier this week, Liverpool and Merseyside UKIP chairmen Stuart Monkham and Adam Heatherington quit the party, claiming Mr Nuttall was "unprofessional" and Mr Banks showed "crass insensitivity" about the disaster.
UKIP leader Paul Nuttall told the BBC on Tuesday that he spent "three hours" on Monday giving a witness statement to Operation Resolve - one of the two criminal investigations ordered following the publication of the Hillsborough Independent Panel's report in 2012.
He was interviewed after he said he attended the 1989 match as a 12-year-old boy with his father and two uncles.