Six Nations/England v Ireland: If Jason Robinson's try in the World Cup final represented the pinnacle of rugby league's contribution to rugby union, then the dropping of Josh Lewsey from the England squad this week could be said to have marked its nadir.

Even as England fell apart following their triumph in Sydney, and as the Lions imploded in New Zealand last summer, Lewsey had looked the most effective back in Europe. In Edinburgh and Paris, however, he appeared to have been transformed from a swift, flexible raider and an intelligent defender into a predictable crash-ball runner of negligible defensive value.

Whatever the reason for the sudden decline of a player previously noted for his reliability, Lewsey's fall put the spotlight on the work of Joe Lydon, England's backs coach, and Phil Larder, the experienced defence guru, both veterans of the 13-man game. This week the pair have been taking far more of the blame than the head coach, Andy Robinson, for the squad's diminished level of performance.

England left Paris last Sunday night knowing all three French tries had been gift-wrapped. Larder's iron curtain, a crucial factor in the World Cup success, lay in ruins. Lydon appeared powerless to energise the team's attacking game, a five-phase move that went nowhere early in the second half. Larder and Lydon were subdued but defiant as they faced the press this week. Larder, who coached Britain to rugby league's World Cup final in 1995, complained he had only 40 minutes on the training pitch this week in which he would be expected to repair disintegrating skills as well as provide a defensive plan for this afternoon's match against Ireland.

The basic skills, in which England proved so deficient last Sunday, could never be taken for granted, he said. "Skills need constant development. But I also have to work on our communication and intensity and on the nullification of the attacking threat posed by the key individuals - people like Brian O'Driscoll, Shane Horgan, Geordan Murphy."

This week Lydon accepted the responsibility for England's failure to score a try in two consecutive matches but rejected criticism of specific areas of the team. "There were fundamental things going wrong," he said, "but it's a game where everybody interacts. You can't just look at one element in isolation."

It was in May 1996 the century-old division between the codes began to break down with the two historic matches between Bath and Wigan and the latter's crushing victory in the Middlesex Sevens. Eighteen months later Clive Woodward invited Larder to join the England coaching set-up but was thwarted when he also attempted to set up the transfer of four top league players in time for the 1999 World Cup. He watched Australia take the title, their defence marshalled by John Muggleton, a former league coach. But by the time the next World Cup came around, Larder's defensive alignment and the arrival of Robinson had helped turn England into world champions.

In terms of influence and personnel, the traffic flowed one way. When Iestyn Harris and Henry Paul joined the Wales and England squads, neither could match Robinson's successful transition. But David Ellis, a former Yorkshire miner, was given a job by Bernard Laporte in 2000, and it was thanks to his defensive drills France muzzled England's attackers so effectively last Sunday.

After England's recent calamities significant voices have been wondering whether the influence of former league luminaries has gone far enough. Among this week's critics of Lydon and Larder is the former England assistant coach Dick Best, who points to Lydon's relative inexperience. "Joe Lydon has a tremendous amount to offer," Best said, "but I'm not sure he's got enough experience at this stage."

Best questioned Larder's influence on the controversial midfield pairing of Mike Tindall and Jamie Noon in recent matches, a policy abandoned for today's fixture. "I think a lot of the selections this season have been based on defence," he said. " . . . we needed to expand a bit and play with a slightly different approach."

Larder and Lydon will be under particularly intense scrutiny today. "The skill level of league is still higher than union, and we're still absorbing some of the lessons," Best said. "But all good things come to an end. Maybe now's the time for a bit of new blood."