social homebuy mortgage provider advice

Julie_A_2

We are housing association tenants that are buying on the open market. Our landlord provides financial support towards the deposit but this places a 2nd charge on the property for 5 yrs (in our case this amounts to 9.5% of purchase price, reducing by 5% yearly each year of the 5 years. Our mortgage broker is having difficulty (as are we independently) with finding a lender that will accept a 2nd charge. Does anyone have knowledge on cooperating lenders?
Thanks