Rachel Whetstone, Uber’s head of communications and policy, is leaving the company following a months long public relations crisis that has left the ride-hailing giant’s reputation in tatters.

Whetstone, who joined Uber in 2015 after a long stint overseeing communications at Google, has struggled to get Uber back on message amid a string of negative publicity, including high-profile allegations of sexual harassment inside the company, a lawsuit accusing Uber of using stolen technology and ongoing criticism about an unhealthy, win-at-all-costs internal culture.

According to memo to employees from Uber CEO Travis Kalanick, Whetstone “decided” to leave the company. Kalanick did not elaborate on why Whetstone was leaving, but praised her talent and said he was “looking forward to having her as an advisor for years to come.”

Whetstone will be replaced by Jill Hazelbaker as Senior Vice President of Global Policy Communications. Hazelbaker worked for Whetstone at Google and joined Uber in 2015, shortly after Whetstone arrived. News of Whetstone’s departure and Hazelbaker’s promotion were first reported by Recode.

In a statement provided to Business Insider, Whetstone said “I am incredibly proud of the team that we’ve built-and that just as when I left Google, a strong and brilliant woman will be taking my place. I joined Uber because I love the product-and that love is as strong today as it was when I booked my very first ride six years ago.”

Whetstone is the latest high-profile depature at Uber in recent weeks. Uber President Jeff Jones, who had been recruited from Target, left in March after only six months. And Ed Baker, Uber's VP of Product and Growth, left the same month.

Meanwhile, sources have told Business Insider that attracting new employees and bolstering internal morale has become increasingly difficult as the company tries to overcome its tarnished reputation.

Uber CEO Travis Kalanick acknowledged some of the problems last month and announced that he would hire a COO to help him manage the fast-growing company. Uber is valued at roughly $69 billion by private market investors and is most highly-anticipated potential candidates for a public offering.

Here's a copy of Kalanick's email to employees about the changes:

"Team, I wanted to let you know that Rachel Whetstone, who heads up policy and communications globally, has decided to leave Uber. Since joining in 2015, Rachel has blown us all away with her ability to get stuff done. She is a force of nature, an extraordinary talent and an amazing player-coach who has built a first-class organization. Importantly, Rachel was way ahead of the game when it came to many of the changes we needed to make as a company to ensure our future success-from promoting cross-functional teamwork to improving diversity and inclusion. Her commitment to excellence in every way is inspiring and I am looking forward to having her as an advisor for years to come, with many more long hikes along the Skyline Trail (attached is picture of my hike with Rach the weekend before last). Rachel is passing the reins over to her longtime right hand Jill Hazelbaker, our newly minted Senior Vice President of Global Policy and Communications. For those of you who haven't met Jill, her background is in politics and she brings deep experience in policy, communications and tech. She's a great team player, terrific at setting priorities and brilliant at seeing around corners. The policy and communications function is incredibly strategic at Uber and I could not be more excited about partnering with Jill to help write the next chapter.
Please join me in thanking Rachel and wishing Jill all the best."