Buildings Insurance for Leasehold Flats

Other

I own a number of leasehold flats - mostly in converted houses, in some cases the entire number of flats in the property. The buildings insurance is arranged by the freeholder but the premiums are really excessive - in some case i can arrange identical cover for 50% cheaper. i have spoken to the freeholder about this and he cites customer service as the reason for using this company.
Is there any way i can force him to change who insures the building if i get the consent of the other owners involved also.