The seats of Perth and Fremantle remain Labor territory after the party comfortably won the final two byelections on Super Saturday.

The Liberal Party decided against contesting the WA seats, leaving them clear for the Labor candidates to almost certainly win, but raising concerns of a poor voter turnout.

Fremantle Labor candidate Josh Wilson, who forced the byelection when he had to quit over dual citizenship issues, hoped to improve the 41 per cent primary vote he secured at the last federal election.

With a third of the vote counted, his primary vote was 52.6 per cent.

Many Liberal voters were forced to send their votes elsewhere.

“I sympathised with them, I pointed out the fact that I’ve been a very hard working local member in the past, that I’ve grown up in this community, that I haven’t got horns, that maybe they need to make an exception and it will be our secret,” he said on Saturday morning.

The lack of a Liberal candidate and expectations that Labor would win had resulted in initial slow pre-polling, leading to expectations of a rock-bottom turnout.

Labor also romped to victory in the seat of Perth, which was the only seat not sent to byelection because of the citizenship issue.

The previous Labor MP Tim Hammond quit the seat for family reasons.

Patrick Gorman, a former Kevin Rudd staffer and state secretary who masterminded Labor’s victorious 2017 WA election campaign, says the AEC should have put out their advertisements earlier rather than “just the last few days”.

The Liberals secured a higher primary vote for Perth than Labor at the 2016 federal election but Greens preferences got Mr Hammond over the line.

The Labor wins in WA followed the party’s byelection victories in the Tasmanian seat of Braddon and the Queensland seat of Longman.