England coach Stuart Lancaster has dropped Dylan Hartley from the World Cup training squad after he was handed a four-game ban this week.

Hartley was found guilty of head-butting Saracens' Jamie George while playing for Northampton in the Aviva Premiership semi-final and was handed a suspension that would have seen him miss England's three World Cup warm-ups and their opener against Fiji on September 18.

Lancaster has deemed that too much of a risk given tournament rules on replacements and injury cover, and has opted to remove him from the squad entirely.

"We are obviously very disappointed with the situation that Dylan has put himself in and where that leaves us as a squad," Lancaster said. "I have spoken to him and he knows he has let himself and everyone down.

"If we selected him in the World Cup squad he would have played no competitive rugby at all and we would be left exposed with only two available hookers in what is a specialised position going into the Fiji game. All it would take is one injury - that is not tournament ending - during the week of the Fiji game and we would only have one fit hooker in the squad for our crucial opening game and this would leave us massively exposed.

"In addition, the regulations also clearly state that in our World Cup squad we must have sufficient cover that is suitably trained and experienced in the front row in case of injury. This is clearly not the case if we begin the tournament with a suspended hooker and as such we have been left with no choice but to replace him.

"It also goes without saying that we need all our players to be able to control their discipline and make good decisions under pressure, the World Cup will clearly require this, and Dylan has not clearly displayed this in this latest incident. This is an area that he still needs to address. Dylan will be replaced by Jamie George in the World Cup squad and will not be considered until the suspension is served."

The news will come as a huge blow for both England and Hartley. He was their first-choice hooker during the Six Nations and is one of the most experienced players in the squad with 66 caps to his name.

The Northampton hooker is no stranger to controversy having accumulated 54 weeks worth of suspensions during his career. The bans have impacted on his international prospects as he was forced to miss the British & Irish Lions tour in 2013 after receiving a red card in the Premiership final.

For England, it is a second disciplinary setback for Lancaster after he opted to exclude Manu Tuilagi from the World Cup mix. The centre pleaded guilty to three counts of assault and one of criminal damage.