The former Afghan intelligence chief Amrullah Saleh announced his support to Abdullah Abdullah for the second round of election.
Saleh in an online statement said the decision to support Abdullah in election runoff was taken after consulting with members of Afghanistan Green Trend.
He said Afghanistan Green Trend members will continue campaigning in favor of Abdullah besides monitoring the election.
Afghanistan Green Trend has nearly 50,000 members and half of the members are university graduates and students.
This comes as Jamil Karzai, a close relative of President Hamid Karzai and former member of the parliament on Wednesday endorsed Abdullah Abdullah for the second round of election.
Other candidates, Zalmai Rassoul and Gul Agha Sherzai have previously announced their support to Abdullah Abdullah during the second round of election.
The election runoff between Abdullah and Ashraf Ghani Ahmadzai is expected to be organized on 14th June, the election commission officials said.