The 35-year-old made the decision because he felt his recent form did not justify his position.

"I think it is important for the team that I bat well at the top of the order and I still hope to score lots of runs for the club," he said.

"Sometimes a change can do the trick. We need to spark into gear as a team and maybe somebody with fresh ideas will help us do that."

Somerset are still seeking an overseas player for next summer and may use the captaincy as extra bait.

County chief executive Peter Anderson said: "Peter has been quite hard on himself. He has been very successful off the field and made a good job of captaining a side that has under-performed."