The controversial fighter from Crumlin took to Twitter to vent his views on Covid-19 vaccines and his belief that Ireland should leave the EU.
He also posted a photo of the Fine Gael spokesman on European Affairs cheering at a football match at the Aviva stadium, implying that the politician was under the influence of ecstasy.
“Were you on E in the Aviva last week?” McGregor posted on his Twitter account @TheNotoriousMMA.
“Happy, sweaty sap. Mandate vaccine is coming per EU. But which one even? 1st? 2nd? Boost? Omicron? And the message to be delivered by the same people will just do as they are told.”
But Mr Richmond shot back with a barb of his own, tweeting: “ Here champ. It’s Neale. But when you’ve picked up that missing e that was right in front of you, you’ll see that EU membership has been good for Ireland & the vaccines have ensured lots of Irish people haven’t died when you were off on some yacht in the Med.”
But his coup de grace was throwing back McGregor’s famous taunt “you’ll do nuttin” which McGregor said to his opponent Nate Diaz during the now infamous press conference ahead of the UFC 202 bout in Las Vegas in August 2016 that descended into a water bottle fight between the pair.
Diaz, clearly angered by McGregor showing up half an hour late for the press conference, walked off the stage uttering expletives to McGregor, who in turn responded:
“Shut your f**kin’ mouth, you’ll do nothing! You’ll do f**kin’ nothing! Not one of you will do nothing!”
Last night McGregor also hit out at mandatory vaccinations saying he is against "forcing anyone to inject something into their bodies."
The comments came as the Crumlin-born fighter blasted the government in a series of late night tweets.
In the posts, McGregor called for a conversation about Ireland to withdrawing from the EU and described the government as "lap dogs."
The ex-champion's social media tweets came after the government announced they were tightening the level of restrictions placed on hospitality in a bid to curb the spread of Covid-19.
The government's decision came after a number of EU states introduced mandatory vaccinations in response to the spread of the virus.
McGregor wrote: "Forcing anyone to inject something into their body they do not wish to is abhorrently wrong.
"I am not against vaccines, I am against not having the choice.
"God bless those who think otherwise."