How much finance I’ll be eligible to if my mum has moved her partner in

I usually get the maximum loan as I’ve always lived with just mum whose income is far below the £25,000. I am going into second year and it has been confirmed I will receive this again. However I plan to do a 3rd and a 4th year at uni and as of the past few weeks my mums partner has moved in. I am worried that for my final 2 years I won’t get anywhere near as much loan although together they still won’t make £25,000 and I will receive no financial support from either my mum or her boyfriend. Considering how low their earnings are and how much I’ve been eligible to the past 2 years, is it likely this will change? Furthermore once my mum has registered him as living here despite him not working yet could this effect what I’m about to receive in the academic year coming even if my loan has already been guaranteed as the max? Thank you.