The first of those prerequisites should be taken for granted. While the second may take some restoring given the poverty of their performances in the championship hitherto, the third ought to serve as a jolting reminder to England of what can happen when the French dare to dabble in the seemingly impossible.

A rejuvenated England team in hot pursuit of the country’s first Grand Slam for ten years will be hard pushed to remember the most definitive example of what the French can achieve by daring to try something which most teams could scarcely imagine, let alone have the nerve to attempt.

They never did it to more outrageous effect than at Twickenham on a fine spring day at the denouement of the 1991 Five Nations, an occasion overloaded with the expectation of two teams going flat out for the Slam. An early penalty miss from full back Simon Hodgkinson proved the prosaic prelude to the French at their daring best.

Those of us lucky to have been there that day will not forget what happened next. Pierre Berbizier caught the ball in-goal after it had missed the far upright and spent a second or two thinking about what to do next, whether to minor the ball and opt for the safety of a drop-out or chance his arm.

That was all the time he needed to sense that a few English backs had been turned in readiness for the usual set-piece restart. Suddenly the French were off and running, Berbizier releasing Serge Blanco from behind his own posts on the first stage of what has long since been acclaimed as Twickenham’s Try of the Century.

Blanco found Jean-Baptiste Lafond infield and the wing’s pass found Philippe Sella darting towards the right touchline. Aware that he was about to run out of space, Sella came inside allowing Didier Camberabero to go wide and keep the move going towards halfway.

When he got the ball, the fly-half had precious little room for manoeuvre. Hemmed in by the touchline to his right and by a cluster of white shirts immediately in front of him and to his left, Camberabero began reducing the odds against him with two flashes of footballing genius.

The first, the most delicate of chips, took a few opponents out of the equation. He delivered the second, a cross-kick over his left shoulder, a split-second before Will Carling could repair the damage.

The ball fell so perfectly for the French left wing to apply the coup de grace, diving over beneath the crossbar and not even Jeremy Guscott at full throttle could stop him.

The left wing in question had run the length of Twickenham to collect Camberabero’s kick on the second bounce and complete a move of rare beauty which had taken 23 seconds to compose from start to finish. So when Saint-Andre speaks of ‘daring’ at Twickenham, he does have some previous.

France lost that day, 21-19 despite outscoring England 3-1 on tries, a fact which contributed to the try being revalued from four points to five the following year. Never, from a Gallic perspective, had so many contributed so much for so little.

England head coach Stuart Lancaster could do worse than show the clip to his young team at some stage during the week, not merely as an antidote aimed at pre-empting any over confidence but a reminder of what the French can do.

That they have not looked remotely capable of doing that in losing to Italy and Wales will heighten English apprehension that the France turning up at HQ on Saturday will be the real thing.

That was supposed to have been the case against Wales in Round Two. Instead the match was so poor and the hosts so inept that the crowd had resorted to entertaining themselves with the earliest of Mexican Waves, after 21 minutes.

By the time they’d done the last one, France had hit rock-bottom of the table.

No French team has finished the championship in outright possession of the wooden spoon during the 44 years since Les Bleus went from first to last in successive seasons.

It happened in 1969 when, after losing their first three matches, Walter Spanghero’s team came from behind to draw 8-8 with Wales at Stade Colombes.

First-half tries from Gareth Edwards and Maurice Richards raised every prospect of a suitably stylish finish following victory at Murrayfield with home wins over Ireland and England.

Instead a second half recovery, highlighted by the goalkicking of Toulouse full-back Pierre Villepreux, cost Wales the Slam thanks to a try from their No.11, Andre Campaes of Lourdes – truly an example of what can be done on a wing and a prayer.

Wales, unchanged after their first international win for 11 months, travel to Rome braced for a sterner test from Italy than France provided in Paris. Their decision to resist any change is due reward for the team in general and one player in particular.

Andrew Coombs, given an unexpected chance at the age of 28 in response to a man-power crisis in the second row, has made a mockery of anyone who saw him as a potential one-cap wonder.

The Dragons lock has made such an impact that he keeps his place against Italy, deservedly so despite the return of a Test Lion in Alun-Wyn Jones, out of Wales action since mid-November.

Scotland, out on their own as the most entertaining team in the tournament with six tries from their two matches, will aim to start against Ireland at Murrayfield on Sunday where they finished against Italy.

For an Irish team beset by the loss of Jonny Sexton, Simon Zebo and Gordon D’Arcy on top of Paul O’Connell, Tommy Bowe and Stephen Ferris, it adds up to a severe test of their resources.

No doubt, though, about the main event of Round Three – England v France. If the French rediscover the power and precision which swept them to emphatic wins over Australia and Argentina before Christmas, who knows they could be good enough to evoke memories of Blanco, Berbizier, Camberabero and Saint-Andre.

For the record, this is how they lined up at Twickenham, March 16, 1991:

England:
S Hodgkinson (Nottingham): N Heslop (Orrell), W Carling (Harlequins, capt), J Guscott (Bath), R Underwood (Leicester); R Andrew (Wasps), R Hill (Bath); J Leonard (Harlequins), B Moore (Harlequins), J Probyn (Wasps); P Ackford (Harlequins), W Dooley (Preston Grasshoppers); M Teague (Gloucester), P Winterbottom (Harlequins), D Richards (Leicester).

Try: Underwood. Conversion: Hodgkinson. Penalties: Hodgkinson 4. Drop: Andrew.

France:
S Blanco (Biarritz, capt); J-B Lafond (Racing), F Mesnel (Racing), P Sella (Agen), P Saint-Andre (Clermont); D Camberabero (Beziers), P Berbizier (Agen); G Lascube (Agen), P Marocco (Clermont), P Ondarts (Biarritz); M Tachdjian (Racing), O Roumat (Dax); X Blond (Racing), A Benazzi (Racing), L Cabannes (Agen). Substitution: M Cecillon (Bourgon), for Tachdjian, 40 minutes.

Tries: Saint-Andre, Camberabero, Mesnel. Conversions: Camberabero 2. Penalty: Camberabero.

Referee: Les Peard (Wales).