Dylan Hartley says France are capable of upsetting England at Twickenham

France were beaten by Italy and Rome and by Wales in Paris in their opening two matches, having started the tournaments as title favourites.

Northampton captain Hartley, who wins back the No 2 shirt from Tom Youngs for 'Le Crunch', says there is no talk in the England camp of a weakened France.

"I wouldn't say they've been awful. They've lost two games, as we did in the autumn when we came back to beat the All Blacks," he said.

"We've got to be very wary of that. A lot of people talk about how unpredictable they can be. We've seen things from their camp saying this is their Grand Slam match, if they can beat us everything is forgiven.

"They can be so dangerous. They have big ball carriers across the back row, a solid front row, dangers out wide.

"The preparation this week has been all about how we're going to win. If we can control that, we can control the game and win.

"We need to keep building on our defence, which has been a rock for us in this tournament.

"We need to strangle them with our defence, not let the likes of Louis Picamoles and Thierry Dusautoir into the game.

"And if we can stop the big ball carriers with offloading abilities we can definitely get stuck in."

Hartley missed the autumn international series through injury and had to bide his time on the bench behind Youngs for the first two rounds of the Six Nations.

But Youngs wobbled in the Aviva Stadium cauldron and, with the set-piece battle a key focus for England, Hartley is ready to take his chance.

"We've talked a lot this week about set piece," Hartley said.

"Against Ireland we had a quarter of the game where we lost four or five set-pieces in a row. I've had to bide my time and wait for an opportunity. This is it. It is now my shirt to lose."