Bartlett, 25, came through Somerset's academy and made his County Championship debut in 2017. In 55 first-class appearances he averages 29.44, with two of his eight hundreds coming this season. In List A, he averages 30.50 with one hundred, but he has been limited to just eight T20 career appearances.

"George is another excellent signing for us and another great addition to our squad," John Sadler, Northamptonshire's head coach, said. "He joins us whilst approaching the prime of his career with some good numbers already behind him.

"He's scored some excellent first division runs this season and I think he'll fit in really well with us and help to drive us forward."

Bartlett was coming to the end of his Somerset contract and keen to further his white-ball game elsewhere, according to Somerset's director of cricket, Andy Hurry. "After speaking with George, a fresh challenge with the opportunity of stronger white-ball opportunities is something we both agree is important for his career ambitions and development", Hurry said.

Northamptonshire are currently bottom of Division One of the Championship and fighting to avoid relegation with four games remaining.

Bartlett said: "I'm very honoured to be joining a great club and I'm really looking forward to getting going. I've had a few great conversations with Sads already and he's really made me feel welcome. Hopefully the boys can finish off this season well and I can make a difference when I join up with them.

"I'm hoping to be a big part of the club. It'll be great to have the opportunity to play all three forms and I'm looking forward to bringing some success."