The British must have their elections no later than 28 January 2025.
The next PM will be from the Labor Party. So the Argies can send a bunch of fishing boats to the Falklands and take them by then. The next PM is extremely unlikely going to act to protect the Falklands. In fact, he may say "it belongs to you". And that will be the end of the dispute.
Considering the mindset of today’s Leftists, I think he’s more likely to threaten to nuke Argentina if they take the islands. Of course if he carries through, London may not be around very long, due to the involvement of other actors.