To Get ILR/PR Must I Be On SAME VISA CLASS For 5yrs

[ESCO]

Hello,
Wonder if anyone can answer my question.
To Get Permernent Residency Must I Be On SAME VISA CLASS For 5Yrs
I am currently working on 2yrs WP visa (Pre Tier 1). On expiry of my 2Yrs WP, I want to change to Tier 1 for 3yrs.
So at the end of 5yrs I would have done 2Yrs (WP) + 3Yrs (Tier1) = 5yrs for PR

I've always thought that to get your PR/ILR you must have been legally resident (with the exception of your years as a studnet) in the UK for 5Yrs.

I just read somewhere (I would try to locate the link and paste later) that after 5yrs, You can get PR/ILR ONLY if you have been on the "SAME VISA CLASS"
for 5yrs (ie if you did 2yrs WP and Extended for another 3Yrs WP all 5yrs must be WP, or all 5Yrs must be Tier 1) , otherwise you cannot get PR/ILR.

Can someone please clarify if this is TRUE or NOT? Any authentic/useful links to the truth would also be helpful

WP - Work Permit, PR - Permernent Residence, ITL - Indefinete Leave to Remain.

Thanks

[vinny]

What immigration category you must be in to apply for settlement and 245E. Requirements for indefinite leave to remain