If you take the government land on lease, the ownership of government shall remain and it shall have its control and can take it back after the fixed period. In such case, the desecration of graves might take place; hence it is better that the land of public graveyard is endowed that where the dead ones are buried forever. The people of the village should struggle for it. However, in the question mentioned above, if there is no way except taking it on lease and the local Ulama and Muftis do not find any problem, it is allowable to take it on lease and make it graveyard.
Allah (Subhana Wa Ta’ala) knows Best
Darul Uloom Deoband