Despite being in the same party as the president, McCain has been one of Trump’s most forceful critics over the last two years, both in the run-up to the 2016 election and its aftermath.

Although he has been undergoing treatment for brain cancer since last summer, McCain has continued to voice his concerns about Trump’s leadership and recently questioned the nomination of a CIA official once involved in torture to lead the spy agency.

“Candid, pragmatic and always fascinating, John McCain holds nothing back in his latest memoir” which is entitled “The Restless Wave” and will be released on May 22, according to the publishers Simon & Schuster.