England can dominate the Six Nations for years to come, says former France fly-half Thomas Castaignede.
Coached by Australian Eddie Jones, England won a first championship since 2011 and can wrap up the Grand Slam with victory over France on Saturday.
Castaignede, who won Grand Slams in 1997 and 1998, told BBC Sport: “There are no other teams near England.
“If they keep the same group of players together, they can win the tournament for many years.”
England secured the title courtesy of Scotland’s win over France on Sunday, which meant they cannot be caught even if they lose in France.
Their success is in contrast to their World Cup display last year, when they became the first tournament hosts to be knocked out in the pool stage.
Jones replaced head coach Stuart Lancaster in November.
Having won all four of his games in charge so far, the former Japan coach can secure a first English Grand Slam since 2003 with victory in Paris.
Former England centre Jeremy Guscott said Jones “promised us changes and he’s delivered”, while ex-Wales fly-half Jonathan Davies added Jones has done “all the right things”.
“England have quality, are very well organised and Eddie Jones brings confidence,” added Castaignede.
“They deserve better than the title, they deserve the Grand Slam. I’ve been really impressed with England and the way they’re playing.”