Former England fly-half Stuart Barnes believes that the Rugby Football Union have taken a "very big risk" in appointing Stuart Lancaster as the permanent head coach of the elite national side.

It is understood that the 42-year-old has been named as the full-time successor to Martin Johnson after an interim stint during the Six Nations, where England won four out of five of their matches.

Despite an impressive run of victories, Barnes believes that Lancaster's true ability would have been tested during the tour in South Africa.

"If you just take the results of the Six Nations it's almost impossible to argue with Lancaster's appointment," Barnes told Sky Sports News. "If you look at the quality of the Six Nations then you're in a different realm.

"England won games but they didn't play great rugby, there was an issue with creativity. My view was that Stuart needed to go to South Africa perhaps to prove that he could do it, not just at the lower tier of the Six Nations but against the elite of world rugby.

"I changed my position and I felt Lancaster certainly deserved a chance to prove he was the man but that was in South Africa. I feel that it's a very big risk giving him the job."

Former Italy coach Nick Mallett was also a strong candidate to take the position.