I think that the first people who make use of mind uploading will be the very rich and powerful. They will lobby to ensure that it is available to them to live on past their mortal meat existence, and get to keep their wealth, influence, and civil rights.
See this question for thoughts on the timeline driven by economics: it will be open only to the wealthy at first and will gradually become possible for middle class etc.
Eventually the uploaded will outnumber the “living”. But long before that, they will be the oligarchs, plutocrats, billionaires, and heads of state from the previous century and the dominant holder of wealth and power.
In order for the luddites to stop them, even at an early stage, would require a movement of the scope and size that topples nation states. Imagine someone who controls a personal fortune of billions and directs corporate assets on the scale of half a trillion; he’s used to making government inquiries against him simply go away, and controlling public opinion not just on products he’s selling but towards his personal positions.
How could the population possibly come together to stop him? In a free republic he controls the masses through advertising and spin, and in a different kind of regime he simply pays off the government (if the government isn’t already the puppet of him and others like him).
Now this is happening to all the aging or ailing über-riche, all over the planet, so the right kind of situation such as a religious backlash or a powerful leader making him or his money “go away” would be a one-off solution for a specific case or culture—you need to stop all of them. As for the one-off, he might get out of that too, defecting to another country that eagerly harbors him (and his money) for a fee; or disappear into the underworld.
So you don’t just have to topple the power base of a nation, but of every nation, with different cultures and styles of government, and prevent it from happening covertly.
In short, you have to prevent advanced technology from existing on a global basis. It has to be cut off at a point where it would require “obvious” infrastructure to build, like chip fabs.
Or, you need a pervasive surveillance state across all nations, to prevent anyone from doing that (and anything else you want to outlaw).
I think, barring the collapse of civilization before that, that it cannot be stopped.