England's hopes of claiming France's Six Nations title are still intact - albeit Ireland remain strong favourites - but where will they need to gain the edge to secure victory at Twickenham on Saturday?

BBC Sport takes a look at five key battles.

Marcus Smith v Romain Ntamack

One of the big talking points of the Borthwick reign so far is who would play at fly-half. Marcus Smith started the defeat against Scotland before Owen Farrell moved from inside centre to reclaim the number 10 jersey for the wins over Italy and Wales.

But it hasn't quite produced the fluidity Borthwick would have hoped for and the experienced Farrell has not been at his best. He kicked the ball away too often against Italy and missed four attempts at goal in Cardiff.

Captain Farrell's below-par performances have meant England's questions over 10 remain, and Smith has been given the nod for 'Le Crunch'- after impressing on club duty for Harlequins.

Smith is capable of penetrating any defence with his acceleration and distribution, while the physicality and hard running lines of Ollie Lawrence at 12 should help the Quins star play to his strengths.

France have no such selection issues and Romain Ntamack is a classy operator with an attacking flair who will be looking to bring the va-va-voom to west London.

Only Finn Russell (four) has made more assists than Ntamack (two) in the 2023 Six Nations. The Frenchman has terrific balance, footwork and distribution in a well-oiled half-back pairing with Antoine Dupont.

His boot is also a weapon as he produced two pin-point cross-field kicks for Thomas Ramos and Ethan Dumortier to score in the win over Italy.

Jack van Poortvliet v Antoine Dupont

Jack van Poortvliet has been England's first choice scrum-half in this year's Six Nations but is yet to hit the heights in his fledgling international career.

The Leicester player won the Premiership under Borthwick's tutelage last season. He now has 10 caps under his belt but the step up to Test level has not been an easy one and at Twickenham on Saturday, he faces the best in the world.

Antoine Dupont has been there and done that, and continues to do so at the highest level.

The France captain is the tournament's leading points scorer (45) after three games and is joint second for the most assists (two).

Add to that a combined total of 315 metres made, which is the third highest, and you quickly realise that most of what France do well goes through their diminutive talisman.

In contrast, England have adopted a pragmatic approach, which appears to be serving them well with two wins in their recent matches.

Van Poortvliet has kicked the ball on 16 occasions in search of territory - only Scotland's Finn Russell has put boot to ball more (18).

When he moves the ball quickly, as he did in the build-up to Anthony Watson's try against Wales, England can cause defences problems. Twickenham will want to see more of the same against Dupont's France.

Ellis Genge v Dorian Aldegheri

Ellis Genge has been a standout performer for England in this championship and he is rewarded for his form with the captaincy in Farrell's absence from the starting XV.

The dynamic prop has tirelessly scrummaged, tackled and carried with real intensity. He continues to grow on and off the field and is seen as a genuine leader of Borthwick's side.

He has made 38 carries in three games with only Italy's Sebastian Negri (41), Ireland's Caelan Doris (41) and Russell (45) having made more.

France are in disarray at tight-head prop with Uini Atonio and Mohamed Haouas both banned, so Dorian Aldegheri will make his first Six Nations start.

Aldegheri has not played for France for two years but has jumped in front of Sipili Falatea, who has been on the bench for the holders' previous three games.

The prop has been a regular for Toulouse and he will line up alongside club-mates Cyril Baille and Julien Marchand in the front row, but the step up to Test level is a big one, and you can expect Genge to be fired up and looking to target his opponent in his first scrum as England skipper.

Maro Itoje v Thibaud Flament

When available, Maro Itoje has been practically un-droppable since making his England debut in 2016.

The Saracens lock struggled in the opening-game defeat by Scotland but improved against Italy and continued his resurgence in Cardiff.

His safe hands and leadership are crucial in the line-out and he has made more successful tackles than any other England player (48).

The problem for England, is the player leading the tackle count in this tournament is his opposite number Thibaud Flament (58).

The lock thrives on taking contact in defence and attack and is a general nuisance in open play, as shown when he charged down Stephen Varney's attempted clearance to score France's first try of their title defence in Rome.

Expect a fearsome battle in the loose.

Alex Dombrandt v Gregory Alldritt

Alex Dombrandt seems to have made the number eight berth his own.

With Billy Vunipola not favoured by Borthwick, the Quins man has taken his tally to 12 caps and is leading from the front with ball in hand and at the breakdown.

Dombrandt has carried on 36 occasions, with only Genge carrying more in an England shirt, and he threw the final pass for Watson's try against Wales. He has been equally influential in defence and has won a team-high three turnovers.

Opposite number Gregory Alldritt has been at the pinnacle for a while but he is not enjoying his most stellar tournament.

A team-leading 72 metres gained in the win over Italy was followed by a mistake at the breakdown which led to Ireland's third try as France's 14-game winning run came to an end.

He was then sacrificed early on as the champions were forced into a reshuffle after Haouas's sending off against the Scots.

Perhaps this is a good time to face the 25-year-old?