The lies which would be..? "Marxism" is applied to such a wide variety and assortment of left wing governments that it's almost impossible to believe they're anything at all what Marx himself believed would actually occur in the future.
Leninism, Trotskyism, Moaism, Stalinism, and a whole host of other -isms each vary in so many technical aspects, it's hard to really call any of them "marxist" if you want to stay true to what Marx wrote (keep in mind he actually wrote history, and contributed quite a bit to sociology, anthropology, and historical theory). "Marxism" is a bad political umbrella term to be honest, because people have used the term to mean pretty much anything they want.
Also, who are you to say that the general idea behind "Marxism" isn't going to work in the future? Neither you nor I can know that. Has it failed? It's still going strong in many places in the world. Sure the USSR collapsed, but for multiple reasons, not simply because of its left leaning government. The fact that it's been legitimized by being a major player on the world scene (in the form of China today, and formerly the USSR), proves it's here to stay for at least many years to come. The failures of past communist governments does not prove it's illegitimacy (Vietnam has been communist for some time).
Indeed, you can't even say that socialism "never works": look at Europe (specifically Sweden...). The socialist governments in Europe, such as France, were all democratically elected. Lenin in fact wanted there to be an elected body from the multiple soviets to form a single governing body. Unfortunately for Lenin, the civil war caused other choices to be made, such as eliminating opposition parties, and Lenin wanted multiple parties for the working class.