The chairman of the Senate Intelligence Committee, Republican Sen. Richard Burr of North Carolina, on Thursday rejected Google’s offer to send Kent Walker, the tech company’s former longtime general counsel, to testify at a hearing on election security in September.

Walker, who was promoted to senior vice president of global affairs and chief legal officer, was expected to testify in Washington D.C. alongside other Silicon Valley leaders, including Facebook chief operating officer Sheryl Sandberg and Twitter chief operating officer Jack Dorsey, on Sept.5, CNET reported Thursday afternoon.