England number eight Nathan Hughes will miss the first three autumn internationals after being banned for six weeks for punching.
The Wasps forward was initially banned for four weeks, reduced from six because of mitigating factors such as good conduct and a guilty plea.
But Hughes tweeted “what a joke” upon leaving the hearing last week, forcing the panel to reconvene on Wednesday.
It was decided Hughes did not merit mitigation and the sanction restored.
Hughes was also charged by the RFU for conduct prejudicial to the interests of the game, and was given a two-week ban to run alongside the six-week suspension.
He can play again on 20 November, but will not be named in Eddie Jones’ England squad on Thursday morning.
Hughes’ absence means England are without their two first-choice number eights, with Billy Vunipola injured.
Sam Simmonds is also out so Bath’s Zach Mercer is set to be named in Jones’ 36-man squad, while Gloucester’s Ben Morgan has also made a late bid for inclusion.
Hughes, 27, had already missed one game, having being put under a temporary ban pending Wednesday night’s delayed decision for punching Gloucester’s Lewis Ludlow.
The Fiji-born forward will miss the first Test against South Africa on 3 November as well as matches against New Zealand and Japan on the following weekends but he will be available for the final game against Australia on 24 November.
Ludlow himself received a four-week ban last week for a separate incident earlier in the same game, having been cited by independent commissioner Andy Blyth for stamping or trampling on Hughes’ Wasps and England team-mate Elliot Daly.