Owner Stewart Donald says he is “desperately trying to get out” of Sunderland and denied that he has acted as a “crook, a charlatan and a thief”.
Donald said his asking price for the League One club is £37.6m and encouraged the fans to unite to buy it.
In a meeting with supporters, he also tried to clear up a number of “contentious” financial issues.
“They said I was killing the club,” he said. “But I’m doing my best, which I appreciate isn’t good enough.”
In an exclusive interview with BBC Radio Newcastle’s Sunderland commentator Nick Barnes, Donald denied reports he is “being awkward in the sale”.
He also discussed reported interest from a number of buyers, including former Black Cats player Micky Gray and Hong Kong businessman Sammy Yu, as well as renewed interest from US businessman Mark Campbell.
The coronavirus pandemic meant the League One season was curtailed early and decided on a points-per-game basis.
Sunderland missed out on the chance to challenge for promotion as a result and that meant serious interest was shelved earlier this year, according to Donald.
“At this current time no-one has provided proof of funds and shown an intent on closing off a deal,” Donald added.
“I know fans want me out and I’m desperately trying to get out.
“Pre-Covid, we were relatively close to a deal, but unfortunately the two or three serious parties that we had at the time quite understandingly said ‘well you don’t even know what your revenue are or when games are starting again, so we will just sort of wait and then we’ll come back to you in due course’.
“I’ve seen the fan groups to try allay fears that I’m being awkward or trying to block the sale. I’m absolutely not. Everything is escalating.”
Guilty of missing out on promotion
Donald, who is the majority shareholder with a 74% stake in Sunderland, said he would offload the club for £37.6m so he can recover what he paid for it.
And in saying that, he addressed using the Premier League parachute payments due to the club to finance his takeover from Ellis Short in 2018.
“Pre-sale all that money will have been passed back to the club,” he said. “So that means the club has had the benefit of all those monies, which I know has been a contentious issue.
“I’ve invested in the football club and I promised to repay those funds, but I don’t want to lose money on the deal. I feel that the football club is in a much better condition than when I purchased it and I’ll take the same money.
“I appreciate that fans might not be happy with where Sunderland is, but what I’m guilty of is not getting the promotion that everyone wanted.
“But I haven’t not achieved that by being a crook, or a charlatan or a thief.”
Donald went on to say he had “offered the club” to fans’ groups to buy.
“I know there have been indications that they may want to move to a trust [to run the club], and it is a big club,” Donald said.
“If Portsmouth could do it, Sunderland can do it. I’ll be more than flexible on the payment terms as Ellis was with me.
“It’s out there in the open and it’s there for anybody.”