Diane James has quit as leader of Ukip after just 18 days in charge.
The 56-year-old said it had become clear in discussions with party officials that she did not have "sufficient authority" to push through changes which she had planned.
Nigel Farage has said he thinks Diane James' decision to quit as leader of Ukip could have been because of an attack she experienced at Waterloo Station.
Shortly after winning the leadership contest, Ms James was spat on and verbally abused on a train platform. Mr Farage said the incident could have caused "a realisation that she'd taken on a job that was going to be 24/7 that was going to involve her having security with her the whole time, I mean you take this job, your life is no longer your own".
The acting Ukip leader added that he would much rather Ms James recognised that the job was not for her now rather than months after accepting the position saying it "isn't where we need to be but it's not the end of the world."
Diane James has quit as Ukip leader before most people knew who she was. What happened?
Bill Etheridge, who stood against Diane James for leadership, said he was disappointed at her resignation adding she was supported by MEPs.
She has been in the role less than three weeks.