For Leasehold house owners, the answer is yes and it’s reasonably straightforward, this is because a ‘freehold’ effectively means ownership of the land a property sits on. The land simply needs to be partitioned (marked on a map) and then sold to the leaseholder.
A leasehold flat owner on the other hand, cannot individually buy their lease. This is because the flat shares its plot of land with the other flats in the block, it does not sit on its own land. A possible alternative however is for a group of tenants to act together and collectively purchase the freehold (collective enfranchisement) they can then grant themselves 999 year leases for £1. The downside is that the procedure is complex and requires good cooperation between tenants.