Jose Mourinho has stoked tensions ahead of Sunday's derby at Old Trafford by accusing Manchester City players of diving.
Speaking on Friday, opposite number Pep Guardiola commented upon a "correct" and "friendly" relationship between the two managers since their arrival in Manchester last year - somewhat at odds with the tempestuous feuding that marked their respective spells at Barcelona and Real Madrid.
Earlier this week, Mourinho suggested Guardiola lied about playmaker David Silva being a doubt for this weekend's clash. Silva has since been declared fit to face United, where City will aim to extend an eight-point advantage over their neighbours at the summit by chalking up a 14th consecutive Premier League victory.
Now the Portuguese has seemingly made another attempted to reopen old wounds with a far more provocative pre-match comment, stating that City's attacking players "lose balance very easily".
"They defend well, they react well to the moment they lose the ball. They have a good dynamic in attack," he said.
"They have creative movements, amazing players, a fantastic coach.
"They have lots of good things. If you ask me one thing that I don't like a lot, it's that they lose balance very easily. A little bit of wind and they fall."
City have won four penalties this season, more than any other side in the Premier League.
Last month, Arsenal manager Arsene Wenger caused controversy by saying Raheem Sterling "dives well" after the England winger went down under a challenge from Nacho Monreal in the area. Sergio Aguero converted - City's second goal in a 3-1 win.
"I know that a derby is something special for the people," says the boss. "For us, it's about three points but I think that for the people it's a good, positive rivalry." #MUFC pic.twitter.com/qnOmnOYIbt-- Manchester United (@ManUtd) December 8, 2017
Mourinho also suggested Guardiola was the beneficiary of favourable treatment from the football authorities with regards the yellow ribbon he has sported on match days and at news conferences over recent weeks to show solidarity with imprisoned politicians in his native Catalonia.
"I think that our political ideology and our political beliefs is something that we have the right to have," said Mourinho.
"We're normal citizens like everybody else in our countries and everybody else in our world.
"I've known Pep for many years, I think I know what Pep feels about his country. But to have it in football? I don't know the rules.
"If the rules allow us to do that, he is a free citizen to do it. But I'm not sure if the rules allow any political message on the pitch. That's just my doubt.
"But I know Pep and I know his feelings like everyone else because it's public about his country."
Asked whether he would act similarly in support of a cause close to his heart, Mourinho replied: "I think I wouldn't be allowed."