One of the leaders of the opposition to council mergers in Sydney's lower north has emerged as a primary challenger to the Berejiklian government's chance of retaining the seat of North Shore.

Carolyn Corrigan, a councillor on Mosman Council, will run as an independent candidate for North Shore, the seat vacated by former health minister Jillian Skinner.

The seat was held by independents Ted Mack and Robyn Read in the 1980s, but has remained solidly Liberal since 1991.

Controversy over the state government's council amalgamation agenda has emboldened local independents, including Cr Corrigan, who was first elected to Mosman Council five years ago.