Citizenship application

[Goiano]

Dear Forum

I have been granted Permanent Residency (Biometric Residence Card) by the Home Office in February 2016.
Prior to that I had a 5 years Residence Permit stamped on my Brazilian passport as a Family Member of a European citizen (Civil partner of an Irish citizen).
I no longer live with my partner but we have never legally dissolved our civil partnership. The Home Office have already been informed of this situation (it was all explained when I applied for my permanent residency last year).
Now I am applying for British Citizenship and got a bit confused as to whether or not I should include my ex-partner’s passport with my application (the form asks to give details of the marital status and it says "You may send your partner's passport").
Although I was first given residency status due to my civil partnership, I don't know if now my application for citizenship should based on the fact that I have been legally living in UK for over 6 years (on my own rights).
I called the Home Office twice to enquire about it and I got a different answer each time.
Would any of you be able to help with this query, please? It will be most appreciated.