Two weeks after stepping down as Speaker of the House of Commons, John Bercow has announced that he will publish his memoirs in February next year.

Titled Unspeakable, the book was acquired by Weidenfeld & Nicolson after significant interest from publishers. The Guardian understands that the deal was “comfortably” into six figures.

The divisive former MP said the book would “describe as clearly as I can what motivated me”, while his publisher promised it would also include Bercow’s verdicts on figures including Tony Blair, David Cameron, Theresa May, and Boris Johnson. If his comments since stepping down are anything to go by, readers are in for an eye-opener: last week Bercow said in an interview with the Observer that Cameron feels he is “born to rule” and that Brexit is “the biggest mistake of this country after the war”.

Unspeakable will also explain the ways in which Bercow, the son of a cab driver in north London, “has sought to democratise the business of Parliament, using the Speakership to champion the rights of backbench MPs and hold the government to account”. It will also see Bercow tackle “head-on his regretted fascination with definably right-wing attitudes”, and describe “his inexorable march to more progressive thinking” since his election as the MP for Buckingham in 1997.

Bercow was elected Speaker of the House of Commons in June 2009. After presiding over one of the most febrile British parliaments in years, he announced this summer that he would be standing down as Speaker and MP. His prominence during the Brexit debate split European media. The Daily Mail once called him an “egotistical preening popinjay [who] has shamelessly put his anti-Brexit bias before the national interest – and is a disgrace to his office”, but the press in Europe reveled in his behaviour. The Dutch newspaper De Volkskrant once wrote that “no one on the British island can call ‘order, order’ more beautifully than John Bercow”, while Radio France Internationale named him its “European of the week”.

“I am delighted that Weidenfeld & Nicolson has agreed to publish my account of a life in politics,” said Bercow. “I made friends and enemies alike, but from start to finish I sought to do the right, rather than the convenient, thing and to be a decent public servant. The story of a rewarding and fortunate career is told in my own words, and readers can make their own assessment of a journey that I enjoyed and they will judge.”

Weidenfeld chairman Alan Samson, who acquired the memoir from Andrew Gordon of David Higham Associates, said the memoirs were “both a grippingly candid narrative of a truly eventful political life, and also a wonderfully vivid tale of how the nation has reached this point in its history”.

“In the last decade John has made sure that Parliament has been able to stand up to the executive by putting MPs before ministers. Whether it is by accepting urgent questions or working hard to determine that the role of parliament is more widely understood by the public, he has played a vital activist role in the government being held to account,” said Samson. “His book will be a hugely entertaining primer for anyone trying to understand the nature of our democracy and the processes of modern politics in this country.”

The announcement of Bercow’s book deal comes a week after he furiously denied claims that he had demanded £1m to appear on reality TV show I’m a Celebrity, which he described as “utterly trashy”. Bercow has previously written books including Incoming Assets: Why Tories Should Change Policy on Immigration and Asylum, which was published in 2005, and Tennis Maestros: the 20 Greatest Male Tennis Players of All Time, which was published five years ago.