The 35-year-old agreed a five-year deal at Meadow Lane at the start of this month for a reported £40,000 a week after leaving Portsmouth at the end of last season.

The former England defender was the most high-profile recruit to the playing staff this summer following County's takeover by Munto Finance and Sven-Goran Eriksson's arrival as director of football.

The takeover deal is now being investigated by the Football League and, after making his debut in last Saturday's shock 2-1 defeat at Morecambe, Campbell appears to have had a change of heart.

The former Arsenal and Tottenham defender has reportedly asked to leave the club and has said his goodbyes to team-mates.