I've heard this argument often. However the fact that we do not have PR yet (since the conversation started since about 1995) doesn't mean there hasn't been change.
So its not so much a question of if but when, what and how. We will see reform, if it will be a proportional system or the non-proportional alternative vote remains to be seen.
What about how? How do we get there? Through another referendum? If so, 2 referendums (one to abolish FPTP , one to pick the next system). Do we have a Royal Comission or a Citizens Assembly? Do we lobby for a private member's bill? If so, what is the content of the bill?
Fortunately there has been enough maturity in the movement to realize that lobbying is an essential component. I'd say its going to take another 2 years to truly identify the most effective targets (media, government, public) and finally have a solid plan on how to get there.