Conor McGregor challenged to blockbuster UFC 300 fight, it would be the biggest fight in UFC history

Conor McGregor has been called out to a blockbuster fight for UFC 300 in what would be the biggest fight in the promotion's history.

UFC 300 is set for April 13 at the T-Mobile Arena in Las Vegas, Nevada, with a historic title fight added to the card.

McGregor was linked with a fight at UFC 300 until he announced his return for the International Fight Weekend in June.

But Nate Diaz has challenged McGregor to a fight at UFC 300, having been scheduled to appear on UFC 200 before the bout was moved to UFC 202.

Diaz took to social media to call out the Irishman.

"I was supposed to headline UFC200. Headline UFC300 would be better," he wrote on X, accompanied with a UFC 200 poster.

McGregor and Diaz have shared the famed Octagon twice and are 1-1 in their epic series.

The Stockton slugger famously stunned the MMA world when he submitted the 'Notorious' at UFC 196 back in March 2016.

But McGregor exacted revenge a few months later at UFC 202 as they had a five-round war.

Both events were hugely successful as they both generated over 1 million pay-per-view buys, meaning a third meeting could be the biggest fight the UFC has ever put on.

A rubber match has been mooted but has yet to come to fruition, with Diaz seemingly keen to return to the UFC following his departure.

The 38-year-old walked away from the UFC after his contract expired as he pursued a boxing match against Jake Paul.

The UFC legend, however, appears to be behind Michael Chandler in welcoming McGregor back to the cage.

The former two-weight UFC champion announced his return in a video uploaded on social media, claiming he will face Chandler at middleweight on June 29.

In a video, he said: "Ladies and gentlemen, a happy new year to you all, I would like to announce the return date for myself, the ‘'Notorious' Conor McGregor.

"The greatest comeback of all time will take place in Las Vegas for International Fight Week, on 29 June. And the opponent: Michael Chandler. And the weight, Mr Chandler: 185lbs."