Simon Cowell threatens to sack Dannii Minogue, Sharon Osbourne

Simon Cowell has sensationally threatened to sack both Sharon Osbourne and Dannii Minogue from the X Factor if they don't put an end to their squabbling - as show bosses finalize contracts for the next series of the ITV talent show.

The last show was overshadowed by tales of Sharon and Dannii’s mutual hatred of each other.

An X Factor insider revealed: "It’s nearly contract time again.

"Sharon said she doesn’t want to come back with Dannii – and Dannii said she doesn’t want to work with Sharon.

"But Simon has banged both their heads together and told them, 'If you don’t shut up – I can replace you both'.

"They don’t have to be best friends – but they do have to work together."

During the middle of the last series, it was revealed that Sharon, 55, left Dannii, 36, in tears during a row just moments before the first live show last October.

Sharon then stunned viewers of Graham Norton’s chat show - by saying the Aussie singer looked like her bum.

Dannii then teamed up with her famous sister Kylie on the show final – and called Sharon an “old witch” on a skit during an ad break.

The X Factor stars’ contracts are due to be negotiated next month. Simon will want them signed soon after.

But the insider added to British newspaper The Sun: "Bosses know that viewers were hooked on the backstage battles between Sharon and Dannii and they want to keep them both on board – it makes for very interesting TV."

The new series of X Factor will hit our screens later this year.