The commission appointed by the Provisional Government had prepared a project, which was debated in the National Congress from 25 November 1830. On 7 February 1831, the National Congress had completed its discussions and approved the Belgian constitution.
The Belgian constitution was a balanced synthesis of the French constitutions of 1791, 1814 and 1830, the Dutch constitution of 1814, and of English constitutional law. However, it did not become an amalgam. On the contrary, it became an original piece of work. The most important elements are still in force.
Belgium became a parliamentary monarchy. The core principal of the constitution was the separation of powers. The three powers were: the legislative, executive and judicial powers.
The legislative power was assigned to the House of Representatives and the Senate, who have to approve the legislation, and the King, who had to proclaim and ratify them. The Members of Parliament and the Senators were elected with an electoral process based on the payment of taxes. This meant that a person had to pay a certain amount of tax to be eligible to vote. Therefore, although they were elected by a very limited number of voters, they were deemed to be the embodiment of the will of the people.
The legislature therefore became the highest instrument of power in Belgium. To be eligible to stand for election to the Senate, even larger amounts of tax had to be paid, and a minimum age of 40 applied. It was established to stop any ill-considered decisions by the House of Representatives.
Executive power was assigned to the King and his ministers. However, the responsibility for government policy came to rest with the ministers. It was decided that no document signed by the King would be legally valid, unless it was also signed by a minister. The ministers on their part, were accountable to the parliament (the House of Representatives and the Senate).
The exercise of judicial power was assigned to the courts. It was determined, that court sessions had to be public in principle. The judges could only be removed from office by a court judgement. A jury system was established for criminal and political offences, and offences by the press.
Also central, were the rights and freedoms that each Belgian was entitled to enjoy. All Belgians were equal before the law. The citizen could not be deprived of his or her freedom in any way, except as ordered by a court. Property rights and the confidentiality of the mail became inviolable. Everybody was free to express their opinion on whatever subject and to practice any religion they chose to. Freedom of education and the press was guaranteed. Finally, it was enshrined in the constitution, that everybody was free to conduct a meeting and establish an association.