Bill Shorten will remain the member for Maribyrnong, deciding against a seat swap which would have placed him in one of the safest electorates in the country.

A boundary redistribution in Victoria shifted about 40,000 people out of Maribyrnong into the new seat of Fraser, which sits west of the Maribyrnong river. On current predictions, Fraser would be held by Labor with a margin of just over 20%.

The boundary redraw left Shorten, who won Maribyrnong with a margin of 12.3% at the last election, with a 9.4% buffer heading into the next election.

Fraser’s favourable Labor leanings, which all but guarantee a Labor MP the seat for as long as they want, had led to predictions Shorten would jump.

But in a letter to members released ahead of a national executive meeting later on Friday, Shorten said he would remain in the western Melbourne seat he has represented since 2007 – because that’s where his house still sits.

“This is not an easy decision,” Shorten wrote to members.

“However, as the majority of voters from the old Maribyrnong electorate will still reside within the boundaries, I advise you of my intention to nominate as the candidate for Maribyrnong.

“My family’s home is in the new seat of Maribyrnong. This weighed heavily on my decision.”

Labor MPs dismissed suggestions Shorten had lost a factional battle for the move.

“He’s the leader of the federal party. If he wanted it, it was his. He didn’t want it. He considered it, but decided against the move,” one said.

Labor remains convinced a general election is imminent and is moving to have all its preselection issues settled as soon as possible, with all sitting MPs expected to be endorsed.

The battle for retiring Victorian MP Michael Danby’s seat of Melbourne Ports had been expected to be won by Nick Dyrenfurth, but after a late insurgency, another candidate, Josh Burns, emerged victorious.

Former local mayor Mary Delahunty had been the preferred candidate for many, with Labor focused on maintaining its gender quotas, but ultimately fell to factional warfare.

The national executive is expected to endorse Burns as the Melbourne Ports candidate when determinations are made next week, leaving replacing Jenny Macklin in her seat of Jagajaga as one of the last thorny preselection issues.

The left’s preferred candidate, Ryan Batchelor, may become a casualty of Labor’s affirmative action rules, with a woman now expected to fill the seat.

Friday’s national executive meeting will formalise a federal takeover of the preselection process, with final decisions on candidates expected to be made next week ahead of Saturday’s five byelections.