Open ended permanent vs just permanent

I work at a university, and have been on successive fixed term contracts for about 6 years. My contract was recently changed to an “open ended contract”, as my post relies on external funding. The university I work for has stated that they now have three type of staff: Fixed Term staff (people in post less than 4 years) ; Open Ended permanent (a newly introduced category those who can no longer be considered fixed term); and permanent (mostly because they were converted to permanent before the new system). Where I work we are all reliant on external funding. The university has a policy of no compulsory redundancies for permanent members of staff. But they don’t consider “open ended permanent ” staff to be part of this.
If extra funding isn’t in place (or even if it is expected but funding letters hasn’t arrived) - the Fixed Term and Permanent Open Ended people will be given 3 months notice, and it’s the case if extra funding isn’t found within that time we will be dismissed. But this won’t happen to the old category of “permanent” staff. I believed that when it came to redundancy you couldn’t select people simply because they were Fixed Term (and it seems to be what is happening, albeit they are renaming us as “open ended”). I’m curious on your views if this is legal?

The disctinctions they are drawing are entirely fictitious. The only difference between a fixed term contract and a "permanant contract" is that the former has notice built in. But employment rights, including the right to claim unfair dismissal and / or unfair selection for redundancy accrue to all employees by virtue of their length of service - not a thing to do with their "type of contract". Making someone redundant without a fair and objective selection simply because they are on a fixed term contract when there are others doing the same job on a "permanant contract" is simply not lawful. And the second category is definitely made up - there is utterly no such ctaegory anywhere except in their heads.