The paper, originally in Arabic, raises 13 questions to the special envoy. In particular, the HNC asks "what would be the mandate of this body [consultative mechanism] and which international document would it be based on."
The HNC claims it doubts the mechanism can contribute to the political transition in Syria, as "it does not make anything to engage" the Syrian government "seriously."
"One of Mistura's goal is not to allow a constitutional or legal vacuum in Syria. What exactly does this term mean?" the HNC asks in its paper.
The HNC also asks for clarifications on how much binding the proposals on drafting the constitution made by the mechanism would be, who would decide on the dates for the mechanism's meetings and their agenda, and what the chairmanship by de Mistura's office would imply.
"In order for us to assess how much necessary and important this mechanism is, we need to see clarifications on all of these points," the paper reads.
On Tuesday, de Mistura distributed to the delegations a proposal paper suggesting to establish a special Consultative Mechanism on constitution and legal matters.
In the paper obtained by Sputnik, de Mistura suggested creating a mechanism, chaired by his office and involving legal experts from both sides and the UN, that could start working immediately and seek to find ways to draft a new constitution for Syria.
Following their meeting with de Mistura on Wednesday, at which the delegation voiced their concerns about the mechanism idea to the special envoy, some members of the HNC started claiming that de Mistura "withdrew his paper," while others from the delegation kept saying he would just re-formulate it.