Australia House in London is the largest overseas polling station for the federal election, with about 14,000 people voting there in 2019.
Numbers this year are expected to be 60 per cent less than that, but voters are just as passionate.
"I've got to come up and make sure the right government gets into Australia while we are away," one male voter told SBS News.
"The choices we make here are going to affect us for the next three years and affect our families back home," another male voter said.
Some have no other option but to make the long journey to London after postal vote ballot papers from the Australian Electoral Commission (AEC) failed to materialise.
"I enrolled to vote as an overseas voter well before the deadline, I got sent a confirmation email from the AEC saying 'yes we’ve got you, we’ll send you ballot papers' and they never arrived," voter Dr Melanie Thomson told SBS News.
"I'm spending the big bucks — it's costing me about $250 to get down here to vote. It's going to take me all day — about 10 hours of travelling — but I need to vote because I'm in such a marginal electorate I know that my vote will count, so I felt compelled to come."
It's believed around three-quarters of overseas polling stations will not be operating this year as part of a wider push to encourage people to vote by mail, with the AEC citing COVID-19 safety protocols.
Australian voter in the UK, Dr Melanie Thomson. Source: SBS News
"Having a visible polling booth where they can come cast their vote and have a visible connection with Australia," Australian Liberals Abroad president Jason Groves told SBS News.
ALP Abroad president Paul Smith said the AEC didn't provide people with "the proper resources" to vote by mail.
"I fear many Australians will miss out because they've closed over 67 polling stations," he told SBS News.
ALP Abroad president Paul Smith. Source: SBS News
"The expat vote has been the difference in key seats in past several elections; when it’s been close the overseas vote has carried key seats it makes the overseas vote very important," he said.
Thousands of Australians have cast their vote at Australia House over 11 days of polling but it's feared many may not count, with complicated rules as to who is eligible to vote overseas.
Australian Liberals Abroad president Jason Groves. Source: SBS News
"They are coming into polling booth filling in their forms, casting their vote and they will be thrown in the bin when they get back to Australia, and I think that's just wrong," he said.
Mr Groves said generally travellers in the United Kingdom are fine — it’s the long-term residents whose overseas voting enrolment details have changed or have expired that will be affected.
Voting in Australia's federal election closes in the United Kingdom on Friday.