Following the 2015 general election and Ed Miliband's resignation, Harman again became acting leader of the Labour Party and Leader of the Opposition after announcing she would stand down from the role once a leadership election had taken place. While interim leader, she made the decision for Labour to abstain, rather than oppose, the Welfare Reform and Work Bill 2015, leading to 48 Labour MPs defying the whip. Harman also made the decision that Labour would vote for having a European Union membership referendum, reversing Labour's pre-election opposition to an EU referendum. After standing down, she became Chair of the Joint Committee on Human Rights in October 2015.