The general counsel of a US labor agency has said in a memo that drivers for ride-hailing company Uber Technologies are independent contractors and not employees.

The recommendation by the office of general counsel Peter Robb, who was appointed to the National Labor Relations Board (NLRB) by US President Donald Trump, was made in a memo. Uber drivers set their hours, own their cars and are free to work for the company's competitors, so they cannot be considered employees under federal labor law, the memo said.

A ruling on the case is to be made by an NLRB regional director, according to a report by Reuters. Advisory memos from the general counsel's office are generally upheld in rulings. Under the National Labor Relations Act, independent contractors cannot join unions and do not have legal protection when they complain about working conditions.

Employees are significantly more costly because they are entitled to the minimum wage, overtime pay and reimbursements for work-related expenses under those laws. The US Department of Labor in a memo released last month said an unidentified "gig economy" company's workers were not its employees under federal wage law because it did not control their work.