Liberal MP Nick Varvaris is set to be a "one term wonder", with his electorate of Barton to become notionally safe for the Labor Party at the next election.
Under draft new electoral boundaries, Barton will gain large Labor-voting portions of the electorates of Grayndler and Watson, and lose strong Liberal areas to the seat of Cook, across the Georges River.
The changes will give Labor a notional margin of more than seven per cent in Barton.
Mr Varvaris just scraped home at the last election, making Barton the Liberals's most marginal seat.
The proposed changes, which can be appealed before final boundaries are set, will undoubtedly lead to a scramble of candidates for Labor pre-selection.
Former Premier Morris Iemma and former Hurstville mayor Steve McMahon, who was the party's candidate at the last election, are likely candidates.
Barton will gain St Peters, Tempe, Marrickville South, Marrickville, Dulwich Hill, Hurlstone Park, Canterbury, Campsie, Belmore South and Clemton Park.
It will lose Kingsgrove and Beverly Hills to the seat of Banks, while Kogarah, Beverley Park, Kogarah Bay, Carss Park, Blakehurst, Sandringham, Sans Souci, Dolls Point, Ramsgate, Ramsgate Beach and Monterey will move to Cook, held by Social Services Minister Scott Morrison.
Roselands and Kingsgrove will move from Barton to Banks.
In other changes, the marginal St George seat of Banks appears to have improved slightly for sitting Liberal David Coleman.
The Liberals have also improved their margins by more than one per cent in the shire seats of Cook and Hughes.
See Tuesday's Leader for a full report.
What do you think of the proposed changes?
