is it legal for my neighbour to put a mobile home on his front garden

[05dazer]

[123everton]

Don't see why not.

[AlBags]

Making it a home for a long or permanent time is a different matter.

[buildersmate]

It may be necessarily be unlawful to site it there. Living in it for anything other than an occasional day/night is another matter. (For the purposes of the violation of the Town & Country Planning Acts the local authority will probably not take action until a month has unauthorised usage has occurred).
It is often possible to seek temporary planning permission to live in one whilst structural / renovation work is occurring on the main house.

[woofgang]

some houses have covenants on them about what you can and cannot do, apart from that its probably lawful.

[boxtops]

This is a duplicate post, there are several answers on the other one.

[buildersmate]

As I later discovered, BT. Very tedious.

[cassa333]

woofgang, covenants are a very costly thing to try and enforce. To try and fail could amount to you loosing your home.

[woofgang]

the question was about the legality, not the enforcement.

[cassa333]

The answer of one question often leads onto the next. Perhaps I was anticipating the next one. :)

Anyway you can have all the covenants in the world. They are meaningless unless you are prepaired to pay a hefty price to try to enforce them.