Having been brought up in the country, I hadn't thought about urban areas, so looked it up. The law on magpies doesn't seem to distinguish between town and country but since discharging a firearm is illegal in most (probably all) urban areas, that would only leave Larsen traps and there are very specific rules as to their use. This is the RSPB summary:
Magpies are fully protected by the European Union Birds Directive [but] The UK Government has derogated (made an exception) from the Directive in relation to control of magpies.
Under annual general licence issued under the Wildlife and Countryside Act 1981 (for which it is not necessary to apply individually), magpies may be killed or taken by 'authorised persons', using permitted methods, for the purposes of:
* preventing serious damage to agricultural crops or livestock
* preserving public health/air safety
* conserving wild birds.
An 'authorised person' is a landowner or occupier, or someone acting with the landowner's or occupier's permission.
Legal control methods
The RSPB does not oppose legal, site-specific control of magpies, as long as control does not threaten the conservation status of the species. The RSPB is seeking to develop non-lethal methods of controlling crows (including magpies) on its reserves.
The Game Conservancy Trust will advice on the use of the Larsen trap. This is a wire cage trap with a spring-loaded door, designed to catch the bird alive. It can be baited with food, or with a live decoy magpie. This is legal as long as the decoy bird is humanely treated and given food and water daily.
The trap must be checked regularly, at least every 24 hrs. Any magpie or crow caught may be humanely destroyed. Any non-target species must be released. Further information is available from the Game Conservancy Trust, Fordingbridge, Hampshire (Tel: 01425 652381).
Magpies may be shot, again only by a landowner or someone acting with the landowner's permission, for the purposes outlined above. Shooting must be well away from public roads and houses, so is seldom possible in urban areas.
It is also legal to destroy a magpie nest, even if it is in use. However, old magpie nests are often used by protected species, such as long-eared owls in rural areas and blackbirds in suburban areas, so check very carefully first.
