By James Ayles For Mailonline
Published: 17:56 GMT, 11 February 2019 | Updated: 17:58 GMT, 11 February 2019
Leinster and Ireland flanker Sean O'Brien will join London Irish when his central contract ends after the 2019 World Cup.
O'Brien has agreed a three-year deal worth around €420,000 per annum (£370,000) with the Exiles, who are currently nine points clear at the top of the Championship.
The back-row forward, 31, has earned 54 Ireland caps and was selected for the 2013 and 2017 British & Irish Lions tours, making five Test appearances.
British & Irish Lion Sean O'Brien will join London Irish after the 2019 World Cup
On joining, O'Brien said: 'This is one of the hardest decisions that I have ever had to make. I have