What is the ruling on brokerage for the actual amount of a government project, if it is paid by the contractor, and the project is awarded by nomination with an agreement between the official and the contractor to add a percentage for the official?

What an official demands for himself is a forbidden bribe, and it is impermissible to offer it, accept it, or seek it, due to Allah's saying: "Listeners to falsehood, devourers of illicit gain" (Al-Ma'idah: 41), and His saying: "And do not consume your property among yourselves in falsehood, and do not present it to the rulers that you may knowingly consume a portion of the property of others sinfully" (Al-Baqarah: 188), and because the Messenger of Allah, peace and blessings be upon him, "cursed the one who offers the bribe, the one who accepts the bribe, and the one who facilitates it."

As for brokerage, if the real amount is obtained without any relation to bribery, then there is no harm in it. The broker should advise the official and the contractor to abandon bribery due to its حرمة (sacred impermissibility).