Boris Johnson said "the buck stops here" as he promised to deliver on Brexit during his first speech on the steps of Downing Street. The Conservative leader reiterated his promise to deliver Brexit by October 31, "no ifs, no buts" during a wide-ranging speech on Wednesday afternoon. Report by Khanomh. Like us on Facebook at http://www.facebook.com/itn and follow us on Twitter at http://twitter.com/itn