Rory Stewart has described Boris Johnson as an “egotistical chancer” who did not understand his own Brexit proposals. In an article in the Guardian’s Saturday magazine the former international development secretary is withering on Johnson’s performance during the Brexit negotiations. He writes: “I had discovered that he did not understand his own Brexit proposals and did not care. Worse, I had learned that he was allying himself with the most divisive forces in the Conservative party and in British politics.” Stewart, who stood to be Conservative leader before leaving the Commons in 2019, shares his horror upon realising that many MPs were planning to back Boris Johnson in 2019. “This shocked me more profoundly than anything that preceded it. Nine years in politics had already been a dismal insight into the lack of seriousness in British politics,” he writes. “To put an egotistical chancer like Boris Johnson into the heart of a system that was already losing its dignity, restraint and seriousness, was to invite catastrophe.” Stewart had worked with Johnson when Johnson was foreign secretary, and said he had witnessed how Johnson had “wreck[ed] a delicate engagement over the Kenyan elections with a single careless phone call”. Stewart, who has recently published a memoir charting his decade in parliament, decried a ministerial merry-go-round system in which he held five different ministerial portfolios in little more than three years, despite little expertise. “I had discovered how grotesquely unqualified so many of us, including myself, were for the offices we were given. I was put in charge of all the prisons in England and Wales knowing nothing about prisons, the Prison Service, the law or probation,” he wrote. Hecriticised UK government incompetence and said many of his parliamentary colleagues did not understand the meaning of a customs union during Brexit negotiations. He also described being asked by Liz Truss, the then environment minister, to create a 10-point plan for the national parks in his first week of taking office, “thus revealing that what pretended to be policy was simply a press release designed to give the illusion of dynamism”, he writes. In his piece, which also charts how the geopolitical and economic landscape has radically shifted since the financial crash, he admits that on many points he too failed to understand how the world was changing as the assumptions of the liberal global order were upended. The former politician is now president of non-governmental organisation GiveDirectly and hosts a popular podcast with Alastair Campbell, the former communications official to Tony Blair. Since its launch in March 2022, The Rest Is Politics, in which the pair discuss and debate national politics and international affairs, has become one of the UK’s biggest podcasts. Earlier this week, the former minister said some fellow MPs came close to killing themselves while he was in parliament, describing how politics placed an “almost unsustainable” strain on people. He told GB News that he “ended up despising [himself]” for trying to advance his career while he was in the Commons. In an author’s note in his book , Politics on the Edge: A Memoir from Within, Stewart acknowledged that his former colleagues will be angry with him for sharing their private conversations, but justifies it by arguing that only transparency can mend the “shameful state” to which parliament has fallen.