England boss Andy Robinson was last night reeling from the worst possible blow to his Six Nations plans - losing World Cup hero Jonny Wilkinson.

The injury-jinxed superstar will miss England's opening two games next month, against Wales in Cardiff and France at Twickenham.

Wilkinson's latest setback - a partial medial ligament tear - will extend his exile from international rugby to 15 months.

Robinson, currently preparing for a first Six Nations campaign at the helm after succeeding Sir Clive Woodward, had already lost centres Mike Tindall and Will Greenwood, flanker Richard Hill and number eight Martin Corry from the February 5 Millennium Stadium opener.

England captain Wilkinson faces up to six weeks sidelined after being hurt during Newcastle's Heineken Cup defeat against Perpignan in France on Sunday.

He arrived back at Newcastle Airport last night on crutches.

His chances of lining up for the world champions against Ireland on February 27 are probably 50-50 at best, effectively removing him completely from England's biggest challenges. Their last two games are at home to Italy and Scotland.

It also raises serious questions about his Lions tour prospects in New Zealand next summer, given such a prolonged absence from the Test match arena.

A serious shoulder and neck problem put him out of rugby for eight months last year; then an injured bicep meant another two months' inactivity.

Wilkinson said of his injury: ''It's enormously frustrating, having come back from injury twice already this season, to have to miss even more rugby.

''It felt at the time like I had taken a hit, but I am told from people on the sidelines that it wasn't, it just felt like that because of the pain. Now I have to focus on getting past this, and I am determined to put it behind me and come back even stronger.

''I have recovered from injuries before, and I am totally focused on moving onwards from here.''

During Wilkinson's absence, England lost six games from 11 starts in 2004 - and their Six Nations chances have receded without his talismanic presence.

Sale playmaker Charlie Hodgson will continue in the number 10 jersey against Wales, but it is understood Robinson was considering Wilkinson for duties at inside-centre.

The coach's midfield options - or rather, a worrying lack of them - could mean an international reprieve for Henry Paul, who was substituted after just 26 minutes of the defeat against Australia in November, or even a recall for Test veteran Mike Catt.

Stuart Abbott, Ollie Smith, Jamie Noon and Olly Barkley will also be in the equation, with Robinson due to announce the latest England elite player squad later this week.

But he could be tempted to spring a surprise by switching Jason Robinson from full-back to centre, a position from where he started England's Six Nations campaign last season.

''This is Jonny's third injury in a row, and to be out for four to six weeks is bitterly disappointing,'' said Robinson, who spoke with Wilkinson yesterday.

''He is a very good healer, so we have just got to wait and see. The Ireland game would be the earliest we can hope for.''

Further specialist opinion will be sought today on Wilkinson's condition, but the psychological scars of yet another injury may take a long time to heal.

''It is the sort of injury that means he should be able to come back playing the minute he is available,'' said Newcastle rugby director Rob Andrew.

''It is just a matter of when he is happy with the knee and feels comfortable.

''Early March is the prognosis today for his return. This is a blow for everyone - Jonny, us and England - and it is extraordinary that he has had three injuries which are totally unrelated.

''He had an MRI scan on Saturday night, and there is quite a lot of relief that it is not as bad as it could have been.''

Newcastle will be missing him for their crucial Heineken Cup clash against Newport Gwent Dragons at Kingston Park next Sunday.

But the situation is compounded by potential fly-half deputies Dave Walder and Matt Burke currently carrying injuries before a game Newcastle must win in their quest for a quarter-final place.

England, on top of losing retired World Cup stars like Martin Johnson, Lawrence Dallaglio and Neil Back, must now begin 2005 with injuries taking centre stage.

Robinson has no option but to re-structure his midfield, while also re-working the back-row equation in Corry's absence.

Jason Robinson, meanwhile, is likely to continue as captain - after filling in for Wilkinson during the autumn Test appointments with Canada, South Africa and Australia.

England remain strong in many key areas, such as the back three and front five, but they have clearly shown they are far from the finished article without Wilkinson's dynamic presence.

Australia (twice), New Zealand (twice), France and Ireland all beat them last year - and just when he appeared poised to make a long-awaited England comeback injury has laid their key man low again.