Germany's Green party on Saturday decided to accept a government decision to close all nuclear reactors by 2022 instead of pushing for an earlier deadline.
Ahead of the extraordinary meeting in Berlin, the party leadership called on members to support the government, although some of the 819 delegates are calling for Germany to abandon nuclear energy as early as 2017.
"Giving up nuclear energy is a victory for the Greens," said the party's co-leader, Claudia Roth.
Chancellor Angela Merkel's cabinet signed this month on a package of bills, prompted by Japan's Fukushima disaster, that foresee Europe's biggest economy being nuclear-free by 2022, and at a faster pace than envisaged.
Germany's nine reactors currently on line are due to be turned off between 2015 and 2022.
The seven oldest reactors were switched off after Japan's massive March 11 earthquake and tsunami knocked out cooling systems at the Fukushima Daiichi plant, causing reactors to overheat and radiation to leak.
Some EU nations have since reproached Berlin for not consulting its European partners before announcing the decision.
The German move could have particular consequences for France which imports electricity from its neighbour.
Source: AFP Global Edition