The prospect of uncontested scrums will remain in the Premiership this season pending International Rugby Board approval of a proposed rule change.
The scrum is considered by many fans to be central to the game
Uncontested scrums occur when one side cannot field a full front row of two props and a hooker because of injury.
A plan agreed by the Rugby Football Union and Premier Rugby would see the side that is unable to field a full front row forfeit another player.
But the RFU requires approval from the IRB before it can ratify the proposal.
Paul Murphy, chairman of the RFU governance committee, said: "This is a good and positive regulation change and we support the Guinness Premiership clubs in their desire to see this happen.
The IRB have strongly advised us not to adopt this until they have formally approved it
"Even though we believe this is a regulation rather than a law change, and therefore subject only to RFU ratification, the IRB has now strongly advised us not to adopt this until it has formally approved it.
"As the sport's world governing body we respect the IRB's position and therefore the regulations relating to uncontested scrums will remain unchanged for the coming season."
Uncontested scrums were introduced on safety grounds but weak scrummaging teams have flouted them with conveniently-timed injuries.
"We are all extremely disappointed we have arrived at this position just two days before the start of the season," said Premier Rugby's Phil Winstanley.
"The RFU has accepted that the proposed changes constituted a regulation change, which needs only RFU approval and not a rule change requiring IRB approval.
"The regulations were approved by the RFU's Management Board and then adopted as a Guinness Premiership regulation by the RFU Council.
"It is accepted and supported as a very positive development and has huge support from the Guinness Premiership directors of rugby.
"It is frustrating that the IRB is to date not endorsing what is a positive development for the game."
The RFU will continue working with Premier Rugby in seeking IRB approval for implementation of the new regulation from the start of the 2007-8 season.