Conor McGregor breaks ranks after alleged nightclub bust-up to have a pop at UFC rival Nate Diaz

Conor McGregor has broken ranks for the first time since he was accused of allegedly assaulting an Italian DJ – to hit out at UFC rival Nate Diaz.

The 33-year-old has been accused of punching and breaking the nose of Francesco Facchinetti ‘for no reason’ after they had ‘spent the evening’ partying together.

Two-weight UFC champion McGregor has yet to respond to the alleged incident in a nightclub in Rome on Sunday.

Conor McGregor (left) and Nate Diaz clash at a press conference in Las Vegas in 2016

But he has taken a shot at Diaz, with whom he twice shared the octagon in 2016 with each man winning one of their two fights.

Diaz has one fight remaining on his current UFC deal and it is understood that the organisation will not offer him another fight unless he agrees to sign fresh terms.

The 36-year-old was bizarrely told by Dominic Cummings, the Prime Minister’s former chief advisor and Brexit mastermind, not to sign a new contract and risk being ‘screwed’.

And McGregor stuck the boot in by replying on Twitter: “Advised by who? Does this lanky streak of p*** think he business savvy or something?

Dominic Cummings, political strategist, gave some unsolicited advice to the American

“Hey bro, you’d 15 fights in the UFC and were on 20k to fight 20k to win hahahaha 15 f fights. In the UFC! Eyelid hanging off your head and handed a 20k check pre-tax. Know who made you.”

The exchange can a day after Facchinetti claimed that McGregor punched him ‘suddenly’ him in the face ‘for no reason’ to his one million Instagram followers.

He said: ‘At this moment I find myself at Parco dei Principi hotel in Rome, I’m not sure when I will post this video but at 2.30am this morning I was attacked by Sir Conor McGregor.

Diaz is one of the most popular fighters in the UFC despite the many losses on his record

‘Yes, that very famous Conor McGregor that threw a punch to my mouth that busted my top and bottom lip. He broke my nose, there was blood, I’ve now cleaned myself up.

‘He attacked me outside The St. Regis in front of 10 of my witnesses, his friends and his bodyguard.

‘He attacked me for no reason seeing as we spoke for more than 2 hours and we had a good time together.’

MailOnline has contacted McGregor’s representatives for comment. He is yet to respond to the allegations, and has been in Italy with his family for a number of days for christening celebrations.