Wayne Barnes has launched a blistering attack on his own referees union as the Rugby Football Union bonuses scandal threatens to further plunge the sport into civil war.

In a letter seen by Telegraph Sport, Barnes accuses the Rugby Football Referees’ Union of imperilling the “credibility of every referee across England” by agitating for a Special General Meeting that will determine the fate of embattled chief executive Bill Sweeney following the Six Nations.

Barnes is England’s highest-profile official, having taken charge of 111 Test matches before retiring after the 2023 World Cup, his fifth tournament. Last September, he was appointed to the RFU board as Senior Men’s Professional Representative.

The RFU has also recently hired Teneo, a crisis management company, to deal with the turbulence caused by the size of the bonuses awarded to Sweeney and other leading executives last November. While it is claimed they will be charging £5,000 a day, the RFU privately claim that it is being given preferential rates and that Teneo would only be employed for a small number of days a month, meaning the total cost would be in the low £10,000s.

Barnes’ intervention may well add more fuel to the fire of the grass-roots revolt. A source said: “This whole episode is such a disaster for the game. It shows where their interest lies, it’s about ego and self-preservation, not the good of the game. They’ve got no shame.”

Barnes accuses the RFRU of using “inflammatory language” by accusing RFU council members of “either being silent or trying to stifle good governance and democracy by actively briefing against it”.

In his letter sent to all referees and referees’ societies, Barnes writes: “When our Union sends an email with language like this, it damages every referee, because if referees can openly criticise other members of the game, why can’t the game openly criticise referees? This is something we have all worked hard to campaign against. The Council members the RFRU accuse of trying to stifle good governance are volunteers of the game, just like you.”

During his career, Barnes was the victim of death threats. Retiring shortly after taking charge of the World Cup final that South Africa won 12-11 against New Zealand two years ago, Barnes said the level of abuse towards him and his family had “crossed a line”.

Barnes also challenges several of the statements laid out in the motion calling for a Special General Meeting, which was backed by an initial 141 RFU member clubs, regarding the scale of the RFU’s losses as well as its backing for promotion and relegation from the Championship to the Premiership.

“The RFRU has thrust referees into headlines,” Barnes writes. “This is not a place where referees should be. I’m very proud to represent referees on the RFU Board and I will continue to do so with the same passion and integrity as I have done throughout my refereeing career. I believe referees should have a strong voice in the game, but this is not the right way to do it and the changes they call for will not improve our game.”

The RFU had already put out a statement in which its professional referees, employed by the governing body, disavowed themselves of the RFRU’s attacks.

The grass-roots rebellion was sparked by the revelation that Sweeney had been awarded a bonus of £358,000 under the Long Term Incentive Plan in which five other executive directors shared a pot of £1 million in the same year in which the RFU made record losses of £42 million and had made dozens of redundancies.

Even with the removal of Tom Ilube as chair, who has been replaced by Sir Bill Beaumont, the former England captain and World Rugby chair, the anger has shown no signs of abating, with many more clubs lending their support to the SGM resolution drawn up by the RFRU and Championship clubs.

The rebels are a broad church encompassing the referees, Championship clubs and many disaffected grass-roots clubs. Even if they are united in their demand for change, their vision of what that change looks like is not necessarily aligned and the RFU may look to drive a wedge between the different factions before the SGM meets following the conclusion of the Six Nations.

The RFRU has received the letter and is considering its response, which it will issue in due course.