The author (creator) of a book or script holds automatic copyright in the UK. If you wrote it, then the copyright belongs to you. Copyright can be inherited through a Contract that is signed denoting transfer of copyright. The Writers’ Guild of Great Britain explains copyright here. There is a good explanation of UK copyright law on Wikipedia.
We receive many submissions and similarities of subject matter can happen. No idea is truly unique.  We develop our own books and scripts alongside our development work as writing consultants, ghostwriters and scriptwriters. Any similarity to any material sent to us is entirely coincidental. We can’t therefore undertake to compensate you if material similar to yours (directly submitted to us or received coincidentally from another source), is subsequently commissioned or produced.