Religious belief in the UK is falling, the UK is a very secular nation and less than half the population believe basic tenets of Christianity such as that Jesus rose from the dead. Even those who are nominally Christian tend to have secular values. It goes so far that Cardinal Keith O'Brien accepts religion is increasingly being marginalised. Cambridge University which is the most prestigious university in the UK supports these findings.
A poll by the Guardian Newspaper suggests more than half the UK population do not believe basic Christian tenets and also the majority think religion is divisive and harmful. 
Wearing models of execution devices round your neck
There have been a few, fairly widely publicised cases when Christians wearing crosses got into trouble. The employers of those Christians didn't like the crosses and some cases have been taken to the European Court of Human Rights. A Scottish Cardinal has encouraged Christians to wear crosses. Perhaps the worthy Cardinal hopes there will be more such cases and the victims of what churches call “religious discrimination' will get sympathy. Proxima Centauri hopes any decision by the European Court of Human Rights will give Non-Christians including atheists similar rights to Christians over wearing relevant symbols.      
These websites are all useful as external links
- Religion does more harm than good - poll 82% say faith causes tension in country where two thirds are not religious
- Religion in the United Kingdom, Diversity, Trends and Decline
- Religion and belief: some surveys and statistics
- UK Christians oppose special influence for religion in public policy
- UK Religion: Final statistics based on the 2011 census
- Christians 'should wear a cross'
- Cardinal Keith O'Brien urges Christians to 'proudly' wear cross