The Lions, who have achieved promotion to the Co-operative Championship for next season, were keen to sign up three of their most influential players who helped them win the Co-operative Championship 1.
Mort, now 22, joined from Leigh for the 2011 season and has scored 21 tries along with 104 goals.
Head Coach Steve McCormack stated “Morty was one of the stand-out players in the whole division and his points-scoring was second to none.
He backed himself at the start of the season. He was exceptional and I’m delighted to get him on board.”
“But he’s another player who had confidence in himself. He’s not cocky but he’s got a nice arrogance and he’s young and enthusiastic.
“His form in the early season was sensational and as the season went on he matured into a very good player.”
25-year-old Ainscough has previously had spells with Widnes, Rochale and Blackpool before joining the Lions, where he hasn’t missed a game at the stand off position.
McCormack commented “Martin’s form has been as consistent as any player in the division and he has been responsible for creating a lot of chances.
“He’s a very under-rated player and one I think will get even better. It was very important we got him snapped up again.”