My wife has a Thai passport in her maiden name and on naturalization she applied for and got a UK passport in her married name in June 2009. When she applied to renew her UK passport she sent off both her Thai and current UK passport, due to expire on 13 June 2019. The Passport Office kept her UK passport and returned her Thai passport saying that they were unable to issue a passport until the names in both passports matched.
So, according to the Passport Office, even if this means returning to Thailand to change her Thai passport to her married, then she must go. Sure she can go to Thailand on her Thai passport, but how does she get back? I'm sure she would be refused entry to the UK if she only has a Thai passport, and the Passport Office in the UK has her shortly to expire UK passport.
Any helpful advice anyone?