Two Ukip chairmen have resigned from the party in response to Paul Nuttall's admittance that "close personal friends" of his did not die in the Hillsborough disaster. Stuart Monkcom, chair of Ukip's Liverpool branch, and Adam Heatherington, chair of Ukip's Merseyside branch, quit over what they described as Nuttall's "upsetting and intolerable" conduct in relation to his comments about the 1989 tragedy in which 96 Liverpool fans were killed.

Speaking on Merseyside's Radio City News, Nuttall was forced to backtrack on repeated comments made on his personal blog and in statements given to the BBC in which said he had close friends who died at Hillsborough.

He added: "That's not from me. I'm sorry. I haven't lost anyone who is a close personal friend. It was people I knew through football. That is something I haven't put out. It is wrong."

Lynda Roughley, a press officer for Nuttall, took the blame for the "mistakes" on Nuttall's website and offered her resignation. Nuttall's website was taken down for maintenance shortly after story about his Hillsborough comments broke and still remains offline.

Just a few days before Nuttall is due to stand in the Stoke-by election, Monkcom and Heatherington have now quit the party, with further resignations from the party also feared. The departed chairmen are also asking whether Nuttall is still fit to lead the party in wake of the controversy.

A statement from Monkcom said: "Although the timing of our resignations is unfortunate in light of upcoming elections, both Adam and I wish to make it clear, where the painful subject of Hillsborough is concerned, with closure not yet in sight, this unprofessional approach and crass insensitivity from high profile people closely within and without Ukip is upsetting and intolerable.

"With this in mind, we wish to apologise to the people of Liverpool and the Hillsborough families for any offence caused and have done what we consider to be the only honourable thing we could do which was to resign and disassociate ourselves from Ukip."

Monkom said he joined the party as he "felt that supporting a libertarian party was the right thing to do in order to effect change within the political system in this country".

He added: "Unfortunately that dream has been shattered and the potential of Ukip has been squandered by people who have demonstrated they are not fit to lead at present."

During a party conference speech in Bolton, Nuttall appeared on the verge of tears and "overwhelmed" after he asked whether he still had the backing of Ukip following the "cruel and evil smear campaign" against him.

Paul Nuttall
The resignations arrive Paul Nuttall is due to stand in the Stoke by-election Andrew Yates/Reuters