Now there are signs that the companies are more likely to be ferocious competitors than allies. Google is preparing to offer its own ride-hailing service, most likely in conjunction with its long-in-development driverless car project. Drummond has informed Uber’s board of this possibility, according to a person close to the Uber board, and Uber executives have seen screenshots of what appears to be a Google ride-sharing app that is currently being used by Google employees. This person, who requested not to be named because the talks are private, said the Uber board is now weighing whether to ask Drummond to resign his position as an Uber board member.

Google is a big investor in Uber, and has been from the beginning. However, this isn’t the first time a Google employee sat on a company’s board and then decided to enter the same market. Eric Schmidt sat on Apple’s board and witnessed the development of the iPhone.