Acting up role

[LynnieLou]

Hi, I've working for the same organisation for 20 years, and we are currently going through a restructure. I've been acting up into a manager role for 2 1/2 years, and although have been paid for this, this has never been made my permanent post. The new proposed structure has not ring-fenced me for the role I currently do, but my previous role has been deleted. Do I have any legal rights to be able to challenge not being provided with the opportunity to apply or be ring-fenced for a role I have been doing successfully up until now? There has been mention of a 4 year rule(to make me permanent) , but can find no reference to that at all anywhere on the internet.