This is very much a common visa category with applicants applying to join their settled civil partner in the UK. It allows you to come to the UK to enter in a civil partnership visa with your UK civil partner. You can come to the UK either on a civil partnership visa or on the basis you wish to enter the UK and enter into a Civil Partnership. This visa category allows you to settle in the UK and later apply to be naturalised as a British citizen.

Original Source: https://www.quora.com/Can-you-stay-in-the-UK-with-a-civil-partnership/answer/My-Legal-Services-1