Armitage has been suspended for what was adjudged a dangerous tackle on wing Tom Biggs, and he must also serve a three-week ban for striking lock Dave Attwood with his knee, but that penalty will run concurrently.
This latest punishment is backdated to 4 November, the date when London Irish suspended him following an internal hearing, and he will be available to play again on 9 December. He will therefore be absent from the Heineken Cup pool stage matches with Edinburgh and Cardiff Blues, as well as Premiership fixtures against against Wasps and Saracens.
The 27-year-old served an eight-week ban for pushing and verbally abusing a doping control officer after Irish’s New Year’s Day game against Bath and was hit with a three-week ban later in the season for striking Northampton fly-half Stephen Myler
Armitage also missed England’s World Cup quarter-final defeat to France for a high tackle on Scotland’s Chris Paterson.
Meanwhile, Saracen’s Owen Farrell has escaped sanction after the RFU decided he had no case to answer despite being cited for a dangerous tackle on Gloucester’s Henry Trinder.