X Factor judge Simon Cowell may have saved John and Edward, but today he blasted them as "deluded" and declared: "They're not aware how bad they are."
Cowell gave his backing to the Grimes twins on Sunday's show - leading to Lucie Jones being given the boot - but today he said they were getting "progressively worse".
ITV has received more than 3,000 complaints about Cowell's decision to back "Jedward" which meant it went to the public vote over who would be dumped from the series.
But in an interview with the GMG Radio network - for its Help For Heroes day - Cowell again turned on the pair.
"They are deluded in such a funny way that they're genuinely not aware how bad they are. They just live in the twins' world.
"I haven't really had a proper conversation with them, but people who have spoken to them say they're just not aware of anything.
"They think they're pop stars and everything's fantastic and they obviously hear something different to the rest of the world," Cowell told presenter Chris Tarrant during the fundraising broadcast.
Cowell - who backed the pair after watching their performance of the Ghostbusters theme on Saturday night's show - said he struggled to think of "constructive" comments after the twins performed each week.
"I sit there thinking 'I've got to get over my personal feelings; I've got to find something positive or constructive to say at the end of this performance'. And each week they get progressively worse and that's when I get frustrated."
But he supported the public's decision to keep the pair in the competition.
"If you allow - which I think is right - the public to determine who wins, you've got to go with it. You don't have to agree with it but you have to go with it."
The Irish twins have become firm favourites with the public despite some erratic performances.
Broadcasting regular Ofcom has also received complaints about the chain of events which led to Jones being ditched and Jedward being saved.