EX-Wales and Lions Skipper Sam Warburton claims Ireland will not be stopped in their pursuit of a second-straight Grand Slam.
The Six Nations 2023 Champions have maximum points after the first three rounds of their title defence.
Ireland coasted past Wales last weekend as the maintained an 11-game unbeaten streak in the tournament.
Andy Farrell's side now face England in Twickenham on Saturday, March 8.
Ireland have been in sensational form during the past two-years with wins in 20 of their past 21 matches, that includes 18 wins in a row at home, and 11 straight Six Nations wins, equalling England's record.
And the former British and Irish Lion reckons Scotland will have a 'good crack' against Ireland but reckons no other side in this year's Six Nations Championship are on Ireland's level.
The 35-year-old former player was speaking on BBC's Rugby Union Daily podcast as he hailed Ireland as the world's best team.
He said: "I think Scotland will have a real good crack.
"I watch Ireland and I'm genuinely in awe of how they're playing. I can cast my mind back to when I was playing for the couple of seasons when Wales were pretty good. We weren't near that level.
"Their work-rate off the ball, both sides in attack and defence. The accuracy is almost unseen at international level. How comfortable they are, everyone just gets into shape so quickly.
"I thought it was crushing for them in the World Cup [losing the quarter-final vs New Zealand] but they've responded so well.
"South African fans will hate me for seeing this, but I still think they [Ireland] are the best team in the world.
"I've just never seen a team that's that complete.
"They're wearing this invincibility cloak that's just such a powerful thing".
Ireland have won three times at the Twickenham since 2010, and will be looking to beat England yet again after they sealed the Grand Slam with a 29-10 win in Dublin last year.
England host Ireland on Saturday, March 9 at 4:45pm in round four of the 2024 Six Nations.
