In reply to deepsoup:
(First off, declaration of interest: I sit on both sides of the fence: I'm a walker, but I'm also a trustee of a similar - smaller - estate in East Anglia).
Englefield seems to have helpful information about access:
https://www.englefieldestate.co.uk/community/public-access
If the campaigners want Right to Roam, presumably the land in discussion would have been mapped as such under CROW in 2000. Yes, there may be a lost footpath, but there are lost footpaths all over the country which the Ramblers are trying to bring back into mapping and recording.
I also know that the estate I am involved in has many husbandry, farming, tenant privacy, health and safety issues that mean that unfettered access to the whole estate is simply not possible, and the trustees bend over backwards to provide wider access in many ways.
How many of the protesters would happily let a group of people walk across their garden which they regarded as their private space ...