A former Wallaby and confidante of broadcaster Alan Jones has become the first Liberal to confirm interest in contesting the blue ribbon Sydney seat of disgraced former Speaker Bronwyn Bishop.

Bill Calcraft, who was coached by Jones at Manly Rugby Club and was a member of his 1984 Grand Slam Wallaby tour of Britain, is being urged to challenge Ms Bishop for Mackellar.

Challenger: former Wallaby Bill Calcraft. Credit:Christopher Pearce

The 56-year-old, who spent a long business career in Europe before returning to Australia last year, confirmed his interest but said much would hinge on Ms Bishop's decision to retire from politics or contest again.

She controls the numbers in Liberal branches on the northern beaches peninsula and some party operatives believe only Rob Stokes, the NSW Planning Minister, whose state seat of Pittwater lies within Mackellar, could topple the former Speaker in a challenge.