At present each province has its own system for considering new proposals. In the Church of England, General Synod openly debates them and votes on them.
The Covenant would oblige provinces
to act with diligence, care and caution in respect of any action which may provoke controversy, which by its intensity, substance or extent could threaten the unity of the Communion and the effectiveness or credibility of its mission (§3.2.5).
This means that the mere possibility of controversy would be enough to caution the decision-makers against any new proposal. To make matters worse the criteria are hopelessly vague.
It may be easy enough to establish the substance of a controversy, though the Standing Committee of the Anglican Communion is left to decide whether any given substance merits intervention.
Extent may be measurable, but no figures are given. Will a development be forbidden if a thousand Anglicans object to it? Or a million? The matter is again left to the Standing Committee.
Intensity of course is not measurable at all. Even if it were, there is no way of deciding that a hundred people feeling intensely upset about something counts for more, or less, than a thousand who think that on balance it is a good idea.
To be realistic, these criteria are not criteria at all. They are an open invitation to the Standing Committee to see what they think. Once this is recognised, we can see that they are also an open invitation to dedicated pressure groups to mount their campaigns against new proposals, using the mass media to maximise the appearance of the opposition's 'intensity' and 'extent'.
Those who are unfamiliar with the state of church politics may think it most unlikely that Anglicans would abuse their Covenant rights in such ways. On the contrary, however, it is precisely the intention to use it like this - in the first instance against the North American provinces - which makes supporters want it.
In the USA many parishes have claimed that they cannot in all conscience accept the authority of their bishop, when the only problem is that they object to a bishop who does not condemn same-sex partnerships. Some parishes and dioceses in the USA have withdrawn from the Anglican church there, and there have already been a number of court cases over ownership of property.
This does not of course prove that they would use the Covenant in a similar way to get their way on other issues, but the Covenant is designed to make the option available.