Mike Tindall has been supported by three former England players after he was dropped from the squad for behaviour at the recent world cup.
The Gloucester centre was also find £25,000 but intends to appeal the RFU's decision.
Will Carling, Martin Bayfield and Austin Healey have since voiced their opinions, criticising the verdict.
"Mike Tindall's punishment is laughable; too severe & far too late. Horse hasn't just bolted, it's died of old age," Bayfield tweeted.
Writing in The Sun, Carling said: "To me, this all smacks of a witch-hunt and I think it very unfair that Mike Tindall has been made a scapegoat for all of England's off-field problems."
Healey added: "25k fine is wrong. Tindall has been made a scapegoat.. he set bad example but ...(Rob) Andrew trying to justify his position."
Tindall's exclusion could spell the end of his 11-year international career. The 33-year-old was part of England's victorious side that won the world cup in 2003.
