This morning I met with Archbishop Desmond Tutu to discuss his widely-publicised comment last month that he was "sufficiently unhappy [with the ANC] not to vote". I was disappointed by his remark, which I viewed as an abdication of responsibility by a person of great moral authority, and so I made an appointment to see him.

I had a very constructive discussion with the Archbishop and have undertaken to send him the executive summaries of all our revised policies so that he has the opportunity to see for himself what the open, opportunity society for all means in practice, and that there is a real alternative to the ANC.

It is surprisingly difficult to get South Africa 's political debate to focus on policy, even in the run-up to an election.

Zuma continues to demonstrate his ignorance by claiming that we have no policies, and therefore no right to exist - but he consistently refuses to debate any policies with us on any public platform, as he did twice this week.

Therefore, Archbishop Tutu's expressed interest in reading our policy summaries is a lead which all South Africans should follow, because the 2009 election will be a watershed event. It will be the most important election since the first democratic election of 1994 - perhaps even more significant than that historic occasion. That is because the real test of a democracy - the ultimate test, in fact - is whether power can change hands peacefully through the ballot box. And, at the moment, the ANC is on the back foot: it is likely to be defeated in the Western Cape - either by the DA on its own, or by a DA-led coalition of opposition parties - and it could run the risk of losing several other provinces too.

But that will only happen if voters go to the polls on election day. That is why they must register to vote, and then - when the time comes - make their cross on the ballot paper.

This weekend, 8-9 November, the Independent Electoral Commission (IEC) is holding a voter registration weekend. Every South African citizen aged 18 and above must register or re-register in order to vote in next year's election. It is our democratic right and duty.

Franklin D. Roosevelt, the President of the United States during the Second World War, once remarked: "The ultimate rulers of our democracy are not a President and senators and congressmen and government officials, but the voters of this country."

This week he was proved right, as millions of American voters turned out in droves to elect Barack Obama the 44th US President. They took back power from their elected representatives. They replaced an administration which they believed had failed them with one that offers the promise of hope and a fresh start.

Early estimates are that nearly 65% of voters in America marked their ballots - the highest proportion since 1908. The increase in voter turnout was partly the result of a massive campaign by the Democrats, who registered and got to the polls hundreds of thousands of new black, Hispanic and young voters. The result? Change.

Next year, South African voters have an opportunity to make their mark for change. They can reject the ANC's closed, patronage-driven society, and opt for the DA's open, opportunity society instead. They too, like their American counterparts, can, in Roosevelt 's words, be the ultimate rulers of democracy. But they must be registered to vote. And that is why the voter registration campaign this weekend is so important.

I never cease to be amazed by people who could not be bothered to register or vote. Just recently I was at a function, and I sat next to a woman who made an excellent speech that was marked by a crisp, closely-reasoned analysis and filled with penetrating insights. She complimented me on my own speech, and said that she would now consider registering for the first time to vote in the next election.

To me, the decision to register (and vote) is not something that needs to be weighed up: it should be instinctive; it should come as naturally as breathing. There are several reasons for this.

Firstly, the struggle against apartheid was waged so that everybody - regardless of their race - could have the right to vote. That right - along with all those that the apartheid government denied or violated - is now enshrined in the Bill of Rights in the Constitution.

It was a long and bitter battle, and many of those who championed non-racial democracy realised they would not see their cause vindicated in their own lifetime. Theirs was the ultimate sacrifice: they did what they did not for themselves, but for future generations. When we do not vote, we not only fail to perform the most basic of our civic duties, but we also diminish the legacy of the very people who helped bring democracy to South Africa . We dishonour their memory.

Secondly, if voters do not participate in elections, then democracy becomes an empty shell - a noble concept stripped of content. Often I hear people say that their vote does not count; that they are powerless to make a difference. But if enough people believe that, it becomes a self-fulfilling prophecy.

In a proportional representation electoral system, every single vote counts. At the last national election in 2004, 77% of registered voters cast their ballot, but because not all eligible voters had actually registered to vote, only 56% of South Africans aged 18 and older actually voted. Most of the people who stayed away from the polls were young people. If every person over the age of 18 had voted, the outcome of that election may have been very different.

Thirdly, by abstaining from voting - or ruling themselves out of the equation altogether by not registering - South Africans are tacitly condoning the ANC's failed policies, corruption, abuse of power, stalled service delivery and maladministration. They are condoning the decline of education.

If people are not happy with the ANC, then they must vote for a better alternative. Abstention is consent: it means consenting to the ANC's disastrous policy on HIV/Aids that cost hundreds of thousands of lives; to its denialism on crime, which has seen the rate of violent crime soar unchecked; and to its failed policy of "quiet diplomacy" in Zimbabwe , which has destroyed millions of people's prospects and threatened regional stability.

Finally, there is a very special reason to vote in the next election:

South African politics has entered a new phase, with the disintegration of the ruling party and the realignment of political parties under the banner of the Constitution.

Nationally, the ANC can be kept below a two thirds majority. But your vote is needed to do it. In some provinces, the DA can take power from the ANC - either alone or in coalition with other parties. But your vote is needed to do it.

If you don't register you cannot vote. If you don't vote you are powerless to make a difference. They say that in a democracy, people get the government they deserve. As the next election gets closer, every South African must ask themselves this: Did you get the government you deserve in 2004?

Once you have answered that question, enfranchise yourself. Take up your place as a full citizen, armed with your passport to power. Register as a voter. And then vote DA - for change.

This article by Helen Zille first appeared in SA Today, the weekly online newsletter of the leader of the Democratic Alliance, November 6 2008

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