Uber CEO Dara Khosrowshahi called on business, labor and government in Washington state to develop a portable benefits system in an open letter co-signed by Service Employees International Union 775 President David Rolf and Civic Venture Partners founder Nick Hanauer.

“The world of work is changing — driven by technological and economic developments that have reshaped the opportunities and challenges for workers in the 21^st century,” the letter stated. “However, the American social safety system, which was designed in the 20th century for a very different economy, has not kept pace with today’s workforce.”

Uber first approached Rolf and entrepreneur Hanauer last year about working together on the creation of a portable benefits system in Washington state.

The initial, state-level portable benefits system envisioned would establish a system of individual accounts that follow workers and enable them to readily change the “nature, structure and intensity” of their work while continuing to have access to social benefits or protections.

According to the letter, the system would also promote the development of “innovative” products and systems that respond to and enhance independent work, establish open platforms to enable all organizations to compete for contributions and create arrangements for social investments from private and public sources.

“We acknowledge that developing a first-of-its-kind scheme will involve business impacts, implications for worker and consumer protection, complexity in market design and regulatory framework and the need for prudential standards,” the letter stated. “We commit to undertaking a collaborative process that involves all stakeholders and seeks to understand and account for these through data, evidence and an open process.”

However, Bloomberg reported the letter was met with immediate pushback on the left, including from some of Rolf’s colleagues. Critics worry that any Uber-designed legislation will make it easier for companies to treat workers like independent contractors instead of employees, and that workers shouldn’t have to give up their chance to win the much broader range of protections that come with employee status.

“This is just a facelift by Uber to be able to look like they actually care about the people who they hire for the services they provide,” Bloomberg quoted Hector Figueroa as saying. Fugueroa is president of SEIU’s East Coast property services affiliate and serves with Rolf on the international union’s executive board. “I just cannot comprehend how today, as a labor leader, I would be encouraging the spread of ‘independent’ work,” he said.