Cape Town - The Democratic Alliance predicted on Thursday that the court ruling allowing expatriates to vote would improve the party's performance in the April 22 elections.
The DA chairperson, James Selfe, said: "We will benefit differentially from this decision."
Selfe said the Constitutional Court ruling that extends the right to vote to all registered South Africans living abroad "represents a great day for our democracy" and a victory for the DA - one of the parties that made representations in the landmark case.
"Most of what we sought to achieve by taking this case to the Constitutional Court has come to fruition.
"The reasons for which you can get a special vote have increased dramatically."
In two judgments, the court ruled that all registered voters living overseas can vote for national assembly representation, provided they notify the commission of their intention by March 27.
Might extend campaign
But the court did not support an application to allow registration overseas, nor a vote for provincial representation.
Selfe said the DA would in coming days decide whether to launch a separate legal bid to secure voters abroad the right to cast ballots for provincial governments as well.
"It is a matter that we need to think through thoroughly."
Selfe said figures have shown that most registered voters reside in the United Kingdom and that the party might extend its campaign to reach the large expatriate community there.
"If we are going to go overseas that is where we are going to go," he said.
It was likely though to rely on volunteers to canvas potential voters instead of flying senior party members abroad.
"There is certainly a number of volunteers who have volunteered to campaign.
"We don't have any firm plans on going to campaign."
Planned to vote
Selfe said the DA could only guess how many extra ballots would be cast abroad as a result of Thursday's ruling, but the party has been contacted by more than 20 000 citizens in foreign countries in recent weeks about the issue.
About 5 170 South Africans overseas who qualified by law before the Constitutional Court made its pronouncement, have notified the Independent Electoral Commission (IEC) that they planned to vote.
Selfe said his party had no regrets about not bringing a legal challenge to the Electoral Act sooner, as it had done so as a last resort after asking the IEC to interpret the act differently but to no avail.