Labor is expected to start the next federal election two seats ahead of its current numbers in parliament after boundary changes.
Labor frontbencher Mark Butler's seat of Port Adelaide is the latest to be recommended for abolition, taking the number of House of Representatives electorates in South Australia down to 10.
Antony Green, the ABC's veteran election analyst, says the likely result from redistributions across the country is the coalition dropping one to 75 seats, Labor up two to 71 seats, while the crossbench keeps five.
The coalition has notionally lost the seat of Dunkley to Labor in the Victorian redistribution.
Labor is expected to gain the new seats of Bean (ACT) and Fraser (Victoria), but lose Port Adelaide (SA) through its abolition.
There will be 151 MPs in the lower house after the next election, up from 150, thanks to the new seats in Victoria and the ACT.
The next half-Senate and full lower house election can be held as early as August 4 this year but must be held by May 18, 2019.
Mr Butler said the Australian Electoral Commission's recommendation was still a draft, but he was "disappointed" at the proposal to abolish the seat he has held since 2007.
"I will be looking at all my options as I continue to serve my community and as we await a final decision by the commission," Mr Butler said.
Labor's Nick Champion says he expects to be the only Labor candidate for preselection in the renamed seat of Spence, which includes many voters from Port Adelaide.
When asked what Mr Butler's future was, Mr Champion said the Labor party was famous for its maturity and "unity", and challenges would be overcome.
Former federal Labor minister Kate Ellis is retiring in the seat of Adelaide, but Mr Butler would have to do a factional deal to win preselection there.
The new seat in Victoria splits Bill Shorten's electorate of Maribyrnong in half, and once Mr Shorten chooses which seat he wants, the remaining seat will go to the new Industrial Left faction.
Objections can still be made against the proposed boundary changes, with the final redistributions announced by July.
