The Democratic Alliance is to "relaunch" itself in order to grow its support base, party leader Helen Zille said on Monday.

Briefing the media at parliament, she said the event would take place in Johannesburg on Saturday.

The change was aimed at attracting people "who share our values, but who have not historically supported us" to vote DA in next year's national and provincial elections.

Describing the relaunch as a "fundamental shift" for the DA, she said it was prompted by research and analysis that suggested it was time for the party to move from being a party of opposition to a party of governance.

DA chief strategist Ryan Coetzee told journalists the SA political landscape had changed fundamentally.

He said Saturday's relaunch would see the DA becoming "fundamentally different" with changes to the party's style and approach. It was "going to look quite different too".

Zille said research showed there were many South Africans who shared the DA's values, but who did not vote for the party.

She said the DA's strategy over the medium term involved looking to win "one or two" provinces in next year's election, winning "many major cities" in the 2011 municipal elections, and taking over at national level in 2014.