SIMON Cowell is at the centre of a spat between David Walliams and Piers Morgan over who will attend his 60th birthday.
The Celebrity X Factor judge has yet to finalise a date for his rearranged bash after David threatened to boycott the event if Piers attends.
Celebrities including Robbie Williams, Amanda Holden and Cheryl Tweedy have all RSVPd positively.
But Britains Got Talent star David, 48, has said he wont go unless the Good Morning Britain hosts invitation is withdrawn.
A friend said: David refuses to be in the same room as his nemesis, and has told Simon its him or Piers.
Poor Simon is stuck between a rock and a hard place. Piers and David may be ITV colleagues, but once the cameras stop rolling they cannot abide one another.
“Its pretty much open warfare now.
David hates Piers tabloid newspaper background, and is fairly snobby about it, whilst Piers thinks David is a bit of a duplicitous d*** nice to his face, and snide behind it.
Last month Simon postponed his birthday bash in London to focus on work matters.