Shaun Edwards has called an end to his consultancy role with London Irish in order to concentrate on his Wales duties.
Edwards has been working with the Irish squad since the start of the season, one day a week.
"After consultation with Roger Lewis, CEO of the WRU, I am to concentrate solely on Welsh rugby in the build-up to Rugby World Cup 2015," Edwards said.
"Thus my consultancy work will cease with immediate effect."
Edwards was left out of the Lions coaching staff by his Wales boss Warren Gatland and it is on the Welsh side that he will now focus.
With Gatland and Rob Howley both away with the Lions in the summer, Edwards will be a pivotal figure for Wales this summer when they tour Argentina.
London Irish director of rugby, Brian Smith added: "I have always been a supporter of Shaun Edwards and that will not change.
"He is a world-class defence coach and has put in place structures, strategies and techniques that we will take forward. I will step up on the defensive side for the remainder of this season.
"We would like to thank him for his efforts over the last six months and wish him well for the future."