Mr Clinton, who held the post for three years, stepped down after the 36 labour members elected Mr Sawyer. Insiders say Mr Clinton was a traditional figure and members felt it was time for change.
Mr Sawyer succeeded Margaret Hodge as leader and served from 1992 to 1994.
'There is a new and optimistic spirit in the country and I'm going to make sure that spirit is felt in Islington,' Mr Sawyer said.
The new deputy leader is Phil Kelly, who was previously chair of the education committee and is a former editor of the left-wing weekly newspaper Tribune.