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Asked if Saturday's opponents have scrummaged illegally during the tournament, England head coach Eddie Jones said: "100%. Terribly illegally."
Jones says his side have a stronger scrum, adding if the laws are enforced England "will get an advantage".
Wales forwards coach Robin McBryde highlighted England's Joe Marler is a frequent infringer at the scrum.
"He definitely needs to scrummage legally otherwise we will be pointing our finger," said McBryde.
Wales, who are one point behind Six Nations leaders England with two games remaining, felt harshly done by at the scrum in their 28-25 win over England in the pool stage of last year's World Cup.
And McBryde said loose-head Marler had been "found out" when England lost to Australia in their next World Cup game.
"There was a big focus on the loose-heads' angles, particularly with [Wales prop] Gethin Jenkins being highlighted," said McBryde.
"So we were very disappointed in that England game to fall on the wrong side of decisions and we felt the problem lay elsewhere."
However, Jones says he is "quite upset" by Wales' approach to the set-piece.
"They play the laws very well," the Australian told BBC Radio 5 live. "They pre-engage all the time, which is against the laws of the game.
"And then they get penalised one or two times at the start of the game, but the referee gets sick of penalising it.
"Because if the referee keeps penalising it, you know what happens? The referee gets criticised.
"We really want to have a scrum contest on Saturday - it's an important part of the game - so we are really hopeful the referee enforces the law in that area."
Jones added: "If you are the referee and you keep penalising Wales for pre-engaging, then all the smart guys in the commentators' box say 'this referee is ruining the game'.
"But they are not ruining the game, it's the team that is scrummaging illegally which is ruining the game.
"So we want the referee to be really hard, and if he has to ruin the game, he has to ruin the game."
England and Wales have accused each other of illegal scrummaging before the Six Nations showdown at Twickenham.