Correct;
PRNAV is RNP 1.0
From the above link
this level of navigation accuracy can be achieved using DME/DME, GPS or VOR/DME.
I'd like to know how you are going to get a < 1nm cross track error by VOR tracking
A lot of the PRNAV stuff on the Eurocontrol site is suspiciously old.
This doc is 2003.
Page 19 6.2-1 of the above PDF is an intriguing piece of text, suggesting that an aircraft with a primary IFR GPS should be automatically PRNAV compliant
And 7.1-1 is an old chestnut... the "mandatory EHSI" requirement. The UK CAA agreed, several years ago, after some flight tests with a PPL/IR member, that this is not necessary. I wonder what the latest on that one is?