In a move that shocked the nation, President Mohamed Morsi cancelled the contentious military-authored addendum to the Constitutional Declaration Sunday afternoon and rewrote the amendments, effectively awarding himself legislative authorities and powers over Egypt's constitution-writing body.

The Supreme Council of the Armed Forces (SCAF) had sparked mass uproar when it dissolved Egypt's parliament and released its constitutional addendum  on 18 June. The contentious changes to the Constitutional Declaration effectively gave the SCAF legislative authority, powers over the Constituent Assembly and a say in the constitution-drafting process.

In addition, the military council protected itself from presidential interference, by stating that current SCAF members decided on all issues related to the armed forces including appointing its leaders. The then-head of SCAF, Field Marshal Hussein Tantawi, was to act as commander-in-chief of the armed forces and remain as Minister of Defence (according to Article 53 of addendum). Many feared that Egypt's first post-revolution premier would be a puppet president. 

This was blown out of the water Sunday when President Morsi unexpectedly cancelled the crucial SCAF addendum and replaced defence minister Tantawi with head of military intelligence Abdel Fatah El-Sisi, as well as retiring SCAF member chief of staff Sami Anan.

Morsi went further still with his countermove.

Previously presidential authorities were outlined in Article 25 and 56 of the 30 March Constitutional Declaration. Legislation, a parliamentary responsibility, was not one of the powers of the president.

After the SCAF dissolved parliament, they assumed the power to legislate in their controversial June amendments.

By cancelling the SCAF addendum and then authoring the 12 August changes, Morsi has assigned these additional "supra" powers to the president: the power to legislate and to issue public policy and the budget (according to sub-point 1 and 2 of Article 56).

With the status of the parliament still uncertain, Morsi now has full power to author, approve and promulgate legislation: an authority not usually ascribed to the executive body.

Questions have been raised about the consequence of this, as the separation of these powers is normally an important check and balance, a criticism initially levelled at the SCAF.

It is, however, expected that Morsi will hand these powers back to the new parliament when it is elected.

Morsi also counteracted another contentious article in the now-defunct 18 June SCAF addendum. Instead of the military council re-selecting the Constituent Assembly, should the current body be unable to complete its work, the president will choose the new Constituent Assembly members.

SCAF's initial article had sparked national uproar back in June as it effectively gave the military powers over the drafting of the new constitution, a criticism which some have now directed towards the president.

However, the president wrote in his document that should he appoint a new Constituent Assembly it will "represent all factions of Egyptian society" and will be done "after consulting with political forces", which was absent from the initial military article.

This addition is perhaps a bid to assuage fears, as one of the main criticisms levelled against the incumbent constitution-drafting body is that it is unrepresentative of Egypt's diverse society. This was a sticking point that prompted mass walkouts of elected members when it was first formed earlier this year.

The president has also lengthened the SCAF's time frame for re-creating a Constituent Assembly, sending the constitution to referendum and for calling parliamentary elections.

What Morsi has chosen to omit from his 12 August constitutional document is also of interest.

One of the divisive articles in SCAF's now-defunct addendum stated that the president could only declare war after the approval of the military council (Article 53/1). With the addendum no longer in existence and parliament dissolved, it is yet to be seen what approval Morsi will now have seek before going to war, if any.

The SCAF had also written that if the country faces "internal unrest which requires the intervention of the armed forces" the president can "commission" the military "with the approval of the SCAF" to maintain security.

Now that the addendum has been cancelled and with the country facing domestic instability in North Sinai, the president may not have to secure the permission of the SCAF should he choose to deploy the armed forces in the coming days.

Bypassing the military council in these ways could be seen to be giving the president greater influence over the military.

However, these issues have yet to be clarified.

The president also chose not to include a rewrite of Article 60 B1 of the SCAF's addendum in his August 12 document, which referred to the drafting of the constitution.

The military council had dictated that should "the president, the head of SCAF, the prime minister, the Supreme Council of the Judiciary or a fifth of the Constituent Assembly find that the new constitution contains an article or more which conflict with the revolution's goals… or which conflict with any principle agreed upon in all of Egypt's former constitutions" they can "demand that the Constituent Assembly revises this specific article."

This point had been criticised by some political forces, as it gave the military a say in the writing of the constitution. In the 1971 Constitution only the president and the lower house of Egypt's Parliament (the People's Assembly) had the authority to contend constitutional articles.

SCAF's point also stipulated that the High Constitutional Court would ultimately decide on the constitutional articles and that its decision was final.

It is still not determined how constitutional articles will be contended and who is authorised to contend or confirm them.

The military have yet to release an official response to these seismic changes. In addition, there are conflicting reports about whether the military council were consulted about its restructure or the cancelling of the document that previously afforded it significant powers.

Certainly Sunday's document is Morsi's most significant move since assuming the presidency.