Mourinho astonishingly accused Paris St Germain of being the dirtiest team his Chelsea side have faced all season - worse even than a League 2 side.
And PSG manager Blanc warned his team to beware of Chelsea's dirty tricks and Diego Costa's provocation.
The bitter exchange came on the eve of the second leg of the last 16 tie at Stamford Bridge tonight, with the two teams standing level stand level at 1-1 after the first leg in France three weeks ago, when Branislav Ivanovic's potentially vital away goal was cancelled out by Edinson Cavani.
Mourinho, who saw key player Eden Hazard fouled an extraordinary nine times in the first leg at Parc Des Princes, said: "I was surprised – a team with fantastic players was the team with a record number of fouls.
"They were the team making foul after foul, the team which stopped Hazard with fouls all the time, the team attacking the man in possession of the ball with two or three players with some very aggressive actions.
Chelsea hold a light advantage - Blanc [AMBIENT]
"Even a player like Zlatan Ibrahimovic came back when they lost the ball and attacked Hazard from behind.
"I thought an English team would never be surprised by aggression, we have aggression in our country.
"But this season we've played against sides from the Championship, against even Shrewsbury from League Two.
They were the team making foul after foul
Jose Mourinho
"But the most aggressive team was PSG. That was a real surprise. With players of such quality, I was expecting more football and less aggression."
But Blanc said: "Costa is a boy who loves contact, loves the challenge, and provoking opposition players. That's something he thrives off.
"It's important not to get caught up in that. I watched the game against Tottenham in the Capital One Cup final and, right from the start, he was looking to do that.
"He's got good physicality, is technically good, but he always tries to provoke a reaction.
"So we have to be as effective as possible in trying to stop him."
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Blanc also warned that Chelsea will lay every trick in the book to protect their away goal advantage.
He said: "Chelsea will try and employ certain tactics to keep things going their way.
"It's about having experience in these big matches. People resort to certain tactics at times."
Mourinho also attacked PSG for promising their multi-million pound players a £180,000 bonus if they beat Chelsea tonight.
He said: "If I could pay to win, I'd pay to win. But more important is the happiness and pride of success than the money.
"Every player at this level has enough money. Football is about passion, the happiness and the pride of victories. They have no price."
