The X Factor's Adam Lambert blasts fellow judge Iggy Azalea

Adam Lambert as labelled Iggy Azalea a diva and says she's threatened because she can't sing. Photos / Getty Images

In case there was doubt left in anyone's mind: Iggy Azalea certainly isn't winning a lot of friends during her stint as a judge on The X Factor.

Off the back of Guy Sebastian's recent revelation that she's been showing up to work "two to three hours late," Adam Lambert has further dug the boot in this morning about her "diva" antics.

He told Aussie radio hosts Rove McManus and Sam Frost he thinks Azalea's attitude issues are stemming from the fact she doesn't know how to sing.

"I've found some sort of common ground with Iggy, we get along, but I've watched her and observed her with other people and she's tricky - she's a complicated girl," he revealed to the breakfast hosts.

"Maybe she's threatened. She doesn't really know anything about singing."

The 34-year-old Ghost Town singer went on to explain it leaves Azalea, 26, in a vulnerable position.

"I mean let's face it, no one's rapping on the show at this point, so it's like 'uhhhh what is she going to say?'" Lambert said.

"I think she's embarrassed that she doesn't know anything about singing - so maybe she's just defensive ... and Guy [Sebastian] and I are giving all this technical talk, so maybe she just feels threatened."

It was the same theme over at Nova FM, where he was chatting with hosts Ryan 'Fitzy' Fitzgerald and Michael 'Wippa' Wipfli.

"I see some of the shenanigans she pulls with other people and I'm like 'Girl, pull it together!' She's such a diva," he ranted.

The singer was particularly critical of Azalea's behaviour toward her contestants on the show.

Adam Lambert says there's no telling what Iggy Azalea will do. Photo / Supplied

"I'm like, 'maybe the people you're mentoring might be kind of important, just a thought ...isn't that why you're here?'" he quipped sarcastically to the hosts.

He explained that off-air, members of her group had even asked him for help with their song choices.

"I don't know if I should talk about it - but they came into my dressing room and were like 'what should we do?' so I just tried to help, off the record. Which I'm probably not supposed to do."

Lambert's comments certainly set the scene for an awkward work environment throughout the rest of the season - but he didn't seem to mind.

"She's [Iggy's] a loose cannon, it's hard to predict what she's going to say, if she's going to show up, if she's going to listen."

Iggy Azalea has come under fire from two of her fellow judges now. Photo / Supplied

It comes just a few weeks after fellow X Factor judge, Guy Sebastian, also dissed Azalea publicly.

"I don't hate Iggy...we clash. I don't know what she's thinking a lot of the time," Sebastian told Sunrise on October 19.

Sebastian appeared on Kyle and Jackie O the same morning and said Azalea had been rocking up to set two or three hours late.

"She's just down the road in a nice hotel we've put her up in, just chilling and watching movies," he said.

Tune in to The X Factor Australia, Saturdays at 7pm on TV3.