Williams, scorer of 45 tries in 62 Tests and last season’s top Six Nations finisher, will miss the Millennium Stadium showdown due to an ankle injury.

The Ospreys star was hurt during Wales’ tournament-opening victory over Scotland last weekend.

He will be replaced in the starting line-up by Scarlets wing Mark Jones, who wins his 44th cap after recently recovering from appendix surgery.

But the loss of Williams is a hammerblow for Wales head coach Warren Gatland, with his team targeting a third successive Six Nations win against England.

England manager Martin Johnson said: “They have lost a very good player, a guy who can turn a game with a bit of skill.”

And Williams, speaking before his withdrawal was confirmed at this afternoon’s Wales captain’s run, admitted he had done everything possible to recover in time.

“Five days ago after twisting my ankle at Murrayfield, I thought I had no hope of being fit for the England game,” he said, in his Powerade blog.

“I actually thought it could even be broken, but it proved to be just a bit of ligament damage, and every day since then I have steadily felt better and better.

“I have been having intense physiotherapy sessions around the clock, as I am desperate not to miss this game.

“They really don’t come much bigger than England in Cardiff.”

Wales though, moved to allay any fitness fears surrounding number eight Andy Powell, who experienced a calf muscle twinge during training yesterday morning.

Wales attack coach Rob Howley, meanwhile, said there were no concerns about Williams’ fitness for the third game of the Six Nations campaign - against France in Paris on February 27.

“We gave Shane every opportunity to be fit, which shows the respect we have for him,” said Howley.

“He worked with the physios and the medical team, but he is not 100%. We all know what the Test area asks of you, physically.

“We are comfortable with Mark coming in. He has never let us down, and he was outstanding against Australia in the autumn.

“We are confident going into the game, but we know it will be a formidable challenge.

“For us, it is about being accurate and taking our opportunities. We have to be good enough when opportunities come our way.”

Wales might be firm favourites to record an eighth Six Nations success in a row against all opponents this weekend - but lock Alun-Wyn Jones insists the reigning champions must tread carefully.

“People can write and talk about England, but when you play England you know you are playing against a formidable side that does the basics well,” he said.

“It’s for other people to make the hype surrounding this game.

“I’ve got a lot of respect for the players within the England camp, but my sole focus is about representing my country to the best of my ability.

“Each game is its own entity.

“We’ve got to expect England to be very confrontational, then try and stem the tide in the first-half, as we did against Scotland last weekend.

“Things haven’t gone well for them in recent games, but sport is a fickle thing and anybody can win on the day.”