England coach Brian Ashton described an "angry dressing room" after seeing his side lose to France at Twickenham.
England failed to make the most of their pressure
Sebastien Chabal made England pay for missing chances with France's winning try inside the last 10 minutes.
"You work incredibly hard by opening up three or four opportunities in the second half and you blow every one of them," said Ashton.
"You don't win big games against good sides playing like that. You don't win World Cups playing like that, either."
England have the chance to put things right when they play the French again next week in Marseilles.
"I hope the messages of today will be taken on board very quickly and not repeated next week," added Ashton.
Next week we will try to pick our best side
France's Sebastien Chabal
England captain Mike Catt echoed the words of his coach.
"It is very disappointing," he said. "We showed a lot of heart but our execution let us down.
"France closed us down well but we seemed to be a bit rusty as a team and we have got to iron out the mistakes."
Ashton will name his 30-man World Cup squad on Tuesday and Catt remains convinced that, despite the defeat, England are on the right track.
"We've come a long way over the last eight weeks and that has put us in good stead to move forwards," said Catt.
World Cup hosts and Six Nations champions, France were playing their first match since mid-June but showed few signs of rustiness.
"It was a good win for us," said Chabal.
"Everything wasn't perfect - we lost a few lineouts in the first half - but next week we will try to pick our best side."