1988: Boris Johnson was fired from his job at The Times newspaper for fabricating a quote in a front-page article.
November 2004: Boris Johnson was sacked from the Conservative front bench for lying about having had an affair (he denied it outright, but it turned out to be true)
May 2015: Boris Johnson committed to lie down “in front of those bulldozers and stop the building, stop the construction of that third runway [at Heathrow]“. Instead, he went on a single day trip to Afghanistan (literally there, and back) on the day the Heathrow expansion vote was held in Parliament, costing the taxpayer £19,366.
March 2016: Boris Johnson claimed on the Andrew Marr show that Crossrail Tunnels had to be made 50% bigger because of a EU directive, just in case German trains needed to run through them. This narrative was contradicted by the Department for Transport, which explained that A) construction was already well under way at the time the directive was adopted, and B) the UK obtained an exemption for Crossrail, so it did not affect the plans in any way whatsoever.