In practice many covenants are hardly ever enforced.
Every house on the estate where I live has a covenant stating that no external TV aerials are allowed. However it's impossible to get a terrestrial TV signal here without a top-of-the-range external aerial, often fitted to the top of a very long pole, so every single house has an external TV aerial!
Further, every house here has a covenant stating the the gardens must be 'laid mainly to lawn' but at least half of the front gardens have been paved over to provide additional parking spaces.
I'd be amazed if the house owners around the corner from me, who religiously mow the grass on what appears to be part of their front garden, ever demand that I cut it for them, even though (because I own a parking space near to, but not adjacent to, that small piece of grass) there's a covenant in my house deeds stating that I must keep it cut.
A covenant has to be 'with another party' and it's that party who is entitled to enforce the covenant. In the case of the houses on this estate, the covenants are with the developers who built the estate over 40 years ago but they almost certainly put those covenants in place just to make sure that they got planning permission and they'd have no interest whatsoever in seeking to enforce them now.
Flonska's link seems to suggest that neighbours can get together to seek to enforce a covenant but
(a) it would be expensive for them ;
(b) it's likely that their action would have to be against the 'other party' in the covenant, rather than the householder who was breaching it. (i.e. they'd have to try to get the estate developer to enforce the covenant, rather than being able to enforce it themselves) ; and
(c) they'd need to show that the covenant 'touched and concerned' their own properties.
Actually getting a covenant lifted though (if youcan't get the 'other party' to agree to it) though can be extremelydifficult, with some cases in the past having needed Acts of Parliament to achieve that aim!
So, if you're either seeking to get a covenant lifted (so that you can park your caravan on your driveway) or enforced (to prevent your neighbour doing so), the first stage must be to contact the 'other party' in the covenant, as it's up to them to decide what will, or won't, be enforced.