English rugby chiefs have admitted they are unhappy with controversial new law changes being trialled in the sport.
The experimental law variations (ELVs) are already being partially trialled by teams from Australia, New Zealand and South Africa in this year's Super 14.
But some northern hemisphere unions are unconvinced about the need for change.
"We have concerns about the ELVs and the proposed process for their introduction," said Rugby Football Union chief executive Francis Baron.
The RFU's stance brings them in line with the Welsh Rugby Union, who expressed similar reservations last week.
The ELVs include downgrading most penalty offences to free-kicks and allowing teams to legally collapse the maul, but their introduction is a controversial topic in the sport.
The powerful southern hemisphere unions of Australia, New Zealand and South Africa are broadly supportive of the changes, but the ELVs have not enjoyed such a positive reception in the northern hemisphere.
Critics, including the likes of Wasps director of rugby Ian McGeechan, have expressed concern about the long-term implications of the changes.
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They suggest that the variations will remove the rolling maul from the sport, reduce the scrum's importance and make union more like rugby league.
The RFU, who did agree to trial some of the changes in last season's County Championship, will conduct a survey of grassroots coaches and players.
"As these ELVs could potentially result in major changes to the laws of the game, the RFU believes it is important to consult those involved in the game at every level and give them an opportunity to express their views," added Baron.
"In order to discover what participants in rugby union in England actually feel, and to assist us in formulating the RFU's response to the proposed changes, the Union has compiled an online questionnaire."
The International Rugby Board's Laws Project Group met the representatives of the Six Nations unions on 27-28 March.
And the IRB is set to hold a key meeting about the ELVs on 1 May, with the future timetable for any changes set to be up for discussion.
The Australian Rugby Union want rugby authorities to introduce the changes across the board by 1 September, and for the November Tests to be played under the ELVs.
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