It's time - to enrol

One vote can make the difference.

In the 1919 federal election, the seat of Ballarat was won by National Party candidate Edwin Kerby with 13,569 votes, defeating – by just one vote – Labor's Charles McGrath with 13,568 votes. Had any one of Kerby's supporters changed their mind, the result would have been different.

Tight elections aren't just a relic of history. At the last election, five of my colleagues in the House of Representatives won their seats by less than 1 percentage point. Had they lost just 1000 of their supporters, the result would have gone the other way. And with fewer Labor MPs, Tony Abbott would now be celebrating his third year as Prime Minister.

This year, the rolls will close at 8pm on Monday 12 August. If you're not on the electoral roll by then, you're missing out on your chance to shape Australia's future. Just about every political observer agrees that this election will be close. And yet too many Australians, particularly young Australians, are not having their say about the future of the country.

Right now, almost 1.4 million eligible Australians – close to 10 per cent – are absent from the electoral roll. By far the largest group of missing voters are young people: nearly half a million 18-24-year-olds are not enrolled. This means that one in two 18-year-olds, and two in three 19-year-olds, risk not having a say at the ballot box.

Australia is unusual among developed nations in having a system of compulsory voting. Introduced for federal elections by a private member's bill in 1924, it slipped into legislation with little debate. Over the period between 1915 and 1942, all the Australian states and territories also adopted systems of compulsory voting. A few other developed nations (such as Belgium and Singapore) also compel their citizens to vote. But most do not.

Compulsory voting reflects the fact that with rights come responsibilities. Just as juries ensure that court decisions reflect society's norms, and the census makes sure that we survey everyone, universal voting is the only way to guarantee that election outcomes reflect the views and values of all Australians.

By not enrolling to vote, younger Australians are sending a message to politicians that says: 'please ignore our issues'. This is a worry because the younger you are, the more policy matters to you. Young Australians are more likely to be affected by increases in university funding and Austudy allowance; will get more use out of the National Broadband Network; and will benefit more from the safety net of DisabilityCare. If we act decisively on climate change, young Australians stand to get the most benefit.

Getting on the electoral roll has never been easier. Recently, I joined Attorney-General Mark Dreyfus at a demonstration of the Australian Electoral Commission's new online enrolment system. In a few minutes, university students Charlotte Barclay and Karina Curry-Hyde signed up to vote on their iPads.

If you know someone who's not enrolled, ask them to take a few minutes on www.aec.gov.au and sign up. Enrolment works on any computer, including tablets and smartphones.

Remember, choosing a government is the responsibility of all of us. Friends don't let friends stay off the roll.

So if you're an unenrolled 18 year old, imagine yourself sitting in an armchair in 2073, surrounded by loving grandchildren. When one of them asks 'how did you vote in the great election of 7 September 2013?', will you have an answer?

Andrew Leigh is the federal member for Fraser, and his website is www.andrewleigh.com.