11/07/2013 18:42 BST | Updated 22/05/2015 10:12 BST

Leona Lewis &Amp; Nicole Scherzinger Take Their Turns As X Factor Guest Judges

Who? X Factor London auditions, at the O2 Arena.

What? Four jam-packed days of auditions in London meant a series of guest judges sitting pretty on the panel - and next up for judging duty? Leona Lewis and Nicole Scherzinger. The pair are no strangers to the show, with Leona being a previous winner and Nicole a former X Factor USA judge, so we can imagine they settled in reasonably comfortably alongside Gary Barlow, Louis Walsh and Tulisa...

nicole scherzinger x factor

Nicole brought some glam to the panel, arriving at the O2 Arena in a structured LBD and towering heels, her hair pulled back into a quiffed ponytail.

nicole scherzinger x factor

Leona, on the other hand, opted for a more conservative approach to her panelist fashion, in a white shirt, loose-fit trousers and oversized waistcoat with huuuuuge statement platform heels. And we're big fans of that Victory Roll hair 'do.

leona lewis tulisa

We feel a bit bad, this 'ooh look at the new girl' all the time means we keep forgetting about poor Tulisa. She's clearly feeling inspired by the beautiful weather we've been experiencing in her splashy summer prints and high hemlines - but we're still waiting for her to pull a big attention-seeking fashion moment out of the bag. (It's coming soon, we can feel it.)

leona lewis x factor

So granted, this game of musical chairs is all very entertaining, but it still remains to be seen as to who will scoop that coveted fourth permanent position once the live shows begin....

Who do YOU think the fourth judge should be? Let us know in a comment below.