Eleven employees comprising engineers and managers at Alphabet Inc’s Google published an open letter on Tuesday, demanding that the company abandon its plans for a Chinese search product that censors results.

Google's search app for China , known as Project Dragonfly, is an experiment not close to launching. But as details of it have leaked since August, current and former employees, human rights activists and U.S. lawmakers have criticized Google for not taking a harder line against the Chinese government’s policy that politically sensitive results be blocked.

Project Dragonfly would enable state surveillance at a time when the Chinese government is expanding controls over the population, according to the letter signed by Google workers, predominately software engineers and researchers. The document also called on management to commit to transparency, be accountable and provide clear communication.

The employees who signed their names on Tuesday’s letter said they had seen little progress, and expect more colleagues to publicly back the push to cancel Dragonfly.

The letter expresses concern about the Chinese government tracking dissidents through search data and suppressing truth through content restrictions.

"We object to technologies that aid the powerful in oppressing the vulnerable, wherever they may be," the employees said in the letter published on blogging service Medium.

The employees said they no longer believe Google is "a company willing to place its values over profits," and cited a string of "disappointments" this year, including acknowledgement of a big payout to an executive who had been accused of sexual harassment.

Google declined to comment on the letter and said the China search project has only been “exploratory.”

Human rights group Amnesty International also launched a public petition on Tuesday calling on Google to cancel Dragonfly. The organization said it would encourage Google workers to sign the petition by targeting them on LinkedIn and protesting outside Google offices.

Google us seeking for a bigger presence in China, but needs government approval to compete with the country’s homegrown internet services. In 2016 a small team that included Google Chief Executive Officer Sundar Pichai began working on China-related projects, including Dragonfly, to bring Google’s search engine back into the country.