Andy Robinson: Reputations at risk on a key weekend but England will punish Tongan failings

It is difficult to imagine a more important World Cup weekend for the four home nations, all of whom face do-or-die matches that will decide their fate in this tournament. England have the most straightforward task – I believe they should beat Tonga comfortably at the Parc des Princes in Paris tonight – while Ireland, who play Argentina at the same stadium on Sunday afternoon, face the greatest challenge. It is not impossible that the British Isles teams will make it through en bloc, and if they do the fierce critics from the southern hemisphere may have a little less to say for themselves. But this is a crucial 72 hours for European rugby. Reputations are on the line.

Much as I admire the way the Tongans have performed in this competition – and in their captain, Nili Latu, they have produced a player who has earned the respect of rugby people the world over – I cannot see them threatening England's progress into the knockout stage. The islanders do not have the depth of squad common to the major teams, and the cumulative effect of their three gruelling matches to date will work against them this evening. They have been operating at their limit since the start of the tournament. Given the resources at their disposal, it is unsustainable.

England have made a big statement by pairing Ben Kay and Steve Borthwick in the second row, because these two outstanding line-out operators have the winning of the game in their hands. Had the Tongan line-out been just a little more effective against South Africa last weekend we might have seen the biggest shock in World Cup history. As it was, they lost three or four important balls on their own throw and came up five points short. England will be much harsher on this Tongan weakness, both in securing possession and in driving the ball they win. People say the champions will lose something from their driving game with Borthwick in for Simon Shaw, but it's pretty marginal. Borthwick is a much stronger forward in that area than some imagine.

Tonga have other issues, not least their defensive game out wide. If England string three or four phases of quick ball together – and against the Samoans last weekend they finally demonstrated that they were capable of doing it – the islanders will be in trouble. They are a big, powerful side in all departments, but they are not the most mobile team on earth. As the Boks showed in their hot spell during the second half, the Tongans do not like being stretched and struggle to cope when the runners get in behind them. This is why I don't want to see Josh Lewsey kicking too much ball from full-back. Leaving aside the fact that it is not the most reliable part of his game – one of his poor kicks resulted in a try for Samoa last weekend – England will be most dangerous with ball in hand.

The kicking game the Tongans fear most is the one belonging to Jonny Wilkinson. The Wilkinson effect was there for all to see last weekend: 22 points with the boot, including two drop goals and a really wounding penalty from inside English territory. Had the South Africans kicked anywhere near as effectively – Andre Pretorius had a rough afternoon with his marksmanship – they would have finished off the islanders long before the final whistle. Wilkinson is highly unlikely to miss the kicks Pretorius missed, and Tonga know it. His presence gives England a good deal of belief; by the same yardstick, it will eat away at Tonga's confidence. It will be a physical encounter, but I see no reason why the favourites should not have the game won well inside an hour.

Ireland's uphill task

Ireland, considered by many before the tournament to be the British Isles side best equipped to make a real go of it, have struggled for rhythm and momentum from the outset, and now find themselves in the desperate position of requiring a four-try victory over one of the form teams, Argentina. What is more, they must prevent the Pumas securing a losing bonus point. If Argentina finish within seven points of Ireland, Eddie O'Sullivan's team will be on the plane home, irrespective of how many times they cross the South American line.

A four-try performance is feasible in any game of rugby, especially if a team have the match won before the last 10 minutes kick in. England put four past Samoa last weekend, two of them in injury time. I can certainly see Ireland winning this game, but the key element for them is to concentrate on the winning of it rather than chasing a specific number of tries. They cannot afford to be distracted by the fine detail of the situation. They must play the Test as they would play any Test and let the scoreboard look after itself, at least for the first hour.

It is possible that the Pumas will make the mistake of approaching the game with a negative mindset, driven by the four-try scenario. We have seen it happen in the past: remember Gloucester's trip to Munster in the Heineken Cup a few years ago? On that occasion, Gloucester knew they would qualify for the quarter-finals if they avoided losing by a certain amount. That knowledge inhibited them, and when push came to shove, it betrayed them. Munster did precisely what they needed to do to qualify at the expense of their opponents, who learnt a hard lesson that day.

Argentina have yet to concede a try in this tournament, let alone four in one match, while the Irish have not looked like scoring heavily. Rather like England against the United States and the Springboks, they are attacking as individuals rather than collectively. But if the Pumas close in on themselves, kick away more ball than they would usually kick away and find themselves behind in the final quarter, the penalty Felipe Contepomi missed at the death in the opening game against France – a miss that allowed the hosts to escape with a crucial losing bonus point – could return to haunt them.

Scots have the edge

Scotland always knew it would come down to this one match with Italy in St-Etienne. Sure, they had a shot at the New Zealanders on their own patch of grass in Edinburgh, but they would not have expected to beat them, even with their strongest players on the field. This meeting with the Azzurri holds the key to everything, for if Scotland can get past them they might fancy a quarter-final against France or Argentina.

I know the Scots have taken a lot of criticism as a result of the New Zealand game, especially in light of Frank Hadden's decision to rest the lion's share of his senior side. But to my mind, the real problem here had nothing to do with Frank's decision. It was a question of the needlessly unsympathetic fixture planning that lumbered the Scots with a six-day turnaround between a seriously demanding match with the All Blacks and a pivotal one with Italy. There was no rhyme or reason to the scheduling, and it shouldn't have happened.

This will be a close game – too close to call with any confidence – but I take the Scots to win. I was impressed by some of their work against New Zealand: their defence held up pretty well under intense pressure and their line-out was excellent. They also have one of the finds of the tournament in Mike Blair at scrum-half, who has played particularly well. Blair disappeared off the radar for a while, and he had to fight hard to reclaim his place from Chris Cusiter, who was a Lion in 2005. If there was a Lions tour tomorrow, I think Blair would challenge hard for the Test position.

The Italians, on the other hand, have disappointed me. There seems to be an air of resignation about them, the feeling that with the outstanding French coach Pierre Berbizier about to leave for pastures new they have reached the end of something. That kind of mood is dangerous, and for this reason, I expect Scotland to maintain their record of reaching the knockout stage of every World Cup.

Wales have not always made it through, and they have quite a challenge ahead of them this weekend. Like Scotland, Fiji rested some important players in the third round of matches, yet still managed to test the famously well-organised Australian defence on occasion. There are similarities between the two teams: they love to attack, they feel most comfortable in the open spaces and they thrive on turnover ball. Wales gave themselves a boost by fighting back against the Wallabies in Cardiff, but I believe the Fijians at least have the potential to win this game. They are fit and fresh, and now they are 80 minutes away from what they would consider a historic achievement. It could be the most thrilling match of the lot.

Player to watch: England's Lewis Moody

During my time as England coach, I took a fair bit of criticism for sticking with Lewis Moody as my first-choice open-side flanker. I made no apologies then, and I make none now. Lewis is not an out-and-out No 7 in the style of Neil Back, his old Leicester clubmate; in fact, he falls between the open-side and blind-side ideals. But I felt a place always had to be found for him, because he brought so much energy and enthusiasm to the team. No one in the England squad has a bigger heart than Lewis, and while he could be frustrating at times – I was sometimes exasperated by the dull penalties he conceded, or the simple errors he made – the biggest frustration was the fact that people undervalued him to such a ridiculous extent. Lewis is a warrior, and as the England back-rowers will find themselves up against another warrior this evening, it is just as well he's there.

I speak of Nili Latu, the Tonga captain. I first encountered him at first hand during the Lions tour of New Zealand in 2005, when he played for the Bay of Plenty in the opening match of the trip. We got off to a real flyer that night but Latu was superb in calming his side and giving them a handhold on the game. In this tournament, he has been one of the stand-out performers. He has put his head and body on the line and taken an awful lot of hammer: if you fixed a player-cam on him, he would undoubtedly receive the World Cup award for bravery. Will he be equally awesome tonight, or will all that the punishment finally take its toll? Speaking as someone who played his rugby in the open-side position, I'm looking forward to finding out.