I changed my first names and surname in UK about 30 years ago, under the Common Law right to do so.
See the extract below.
I got a letter from a police officer who had known me for a few years who said I had changed my name. With that I got a new passport in the new name with no reference to my birth name. I then changed everything else to my new name without any documentation proof whatsoever.
9 years ago I got married in Manila in my new name, albeit that I produced my birth cert in my birth name (that is the only doc which cannot be change). The Consul said I could not use my new name. I sent an Email to the Home Office who put a flea in his ear. When I went back, there was no problem.
A couple of years ago I took up my right to Irish Nationality and have a passport in my new name too. Again I poduced my birth cert and expalined I had excersied my right to change my name. No problem.
I think (know) the advice you were given at the Passport office is wrong and that you need to ask to speak to a supervisor.
In UK there is not law which says one can change their name but also there is no law which says one cannot. So one can. Deed Poll is not a way of changing one’s name but a record that one has done so. A woman changing her name on marriage does not do by any law but by ‘normal practice.’
See here for more info:-
http://www.adviceguide.org.uk/wales/..._your_name.htm
How to change your name
If you wish to be known by a different name you can change your name at any time, provided you do not intend to deceive or defraud another person. There is no legal procedure to follow in order to change a name. You simply start using the new name. You can change your forename or surname, add names or rearrange your existing names.
Although there is no legal way to change a name, you may want evidence that you have changed your name (see under heading Evidence of change of name). However, you cannot change details on your birth certificate, except in limited circumstances.