The 26-year-old went past 100 games for the Falcons this season, and departs having played 103 matches.

Newcastle were relegated from the Premiership after finishing bottom.

"We spent a huge amount of time and effort developing him into a quality Premiership player," director of rugby Dean Richards said.

"We had hoped to keep our squad together, with everyone fighting together to regain our top-flight status.

"Whilst I understand Simon's motivation to play at the highest level it is really disappointing to lose someone of his ability, who we have invested a huge amount of time and effort into."