Mike Catt has joined the England coaching staff ahead of next month's five-match tour of South Africa.
It has been confirmed that the former England international will leave his role with London Irish at the end of the Aviva Premiership season to become part of Stuart Lancaster's team.
"Mike has played at the top level and is highly respected," said Lancaster. "He has done a great job at whilst coaching at London Irish and we are looking forward to working with him on this South Africa tour.
"He is experienced in playing in South Africa and this will be invaluable as we prepare for this challenging and exciting tour."
Catt admitted that the chance to work with some of the nation's best young talent made the opportunity too hard to turn down.
"I was very impressed with England during the Six Nations, not just the way they played but the culture that is developing, and hopefully I can complement what Stuart and Graham are doing," added Catt. "There are some talented young players coming through and the chance to work with them for the Barbarians game and the tour is really exciting.
"I'll be sad to leave London Irish and I want to say a huge thanks to all the players and coaches I have worked with since 2004. Toby Booth in particular deserves massive credit for what and how he has taught me.
"Thanks also to the supporters who have been brilliant over the last eight years and I will take away some lasting memories."
Catt, 40, made 75 appearances in an England shirt.