How does government negotiate contracts?

Not always the Goverment entities are just looking to favour their people interest.
Sometimes other more prosaic aspects pop up on the table, such as fear due to the Arab Spring, will to remain in power against all odds, etc.
You must take into account these interests to be succesful.
My suggestion is just to be open minded and focused on your purpose.
Additionally, Government entities do not consider time, or negotiation time, in the same manner as private promotors or investors.