[big-and-small]

While this is a real problem and I do have relative who had this issue like this there are ways to get new UK passport without paying £600 or changing legal name in other country.

It's just take digging in government rules and arguing. As long as it's not the first UK passport it's doable.

[dtf]

I'd love to hear any advice on that!

My friend went round and round and sent many documents back and forth for over a year trying to renew her British passport, to no eventual avail. UK authorities were extremely unsympathetic and unhelpful. The offending "misnamed" foreign passport was long expired and French authorities required a valid British passport to renew it - she was left without any passport at all for over a year, until the French took pity and provided an alternate path to renew her French passport.

[big-and-small]

Hey. I will ask how exactly it was solved and try to reply here in a day or two. My relative is woman so problem was that she had her original name in a passport from country of origin and UK passport had her name after marriage.