I do not find Chapter 5 of In the Spirit of the Covenant terribly helpful. This first report of the Joint Implementation Commission for the Anglican Methodist Covenant, includes the chapter 'The Bread and Wine of Holy Communion'. In it, from section 5.4.12, the question of the use of the common cup in communion is raised.
As far as I can remember, the first trays of small communion cups were imported from the United States during the first decade of the twentieth century. Today the overwhelming majority of Methodist churches use them. As the report says, the reason is probably non-alcoholic communion wine, introduced around the turn of the century and fears of contacting some infection without the sterilizing effect of alcohol. It appears such an infection from a single common cup is remote, at least it was in 2005. Perhaps swine flu has raised the question again.
The report makes much of the introduction of a large cup to be used with the small cups for largely symbolic purposes at Methodist Communion services. I'm sure it wasn't around in the seventies when I first attended communion services. It serves no obvious purpose and in my own church it is empty throughout the service. The report says it is symbolic of the unity represented by the common cup. I suspect most Methodists don't know why its appeared and have never been asked. The new worship book suggests lifting the chalice at one point but I have seen ministers raise one of the small cups. That one stands for all makes sense to me.
On balance I would rather not have the large cup. To me it is an unnecessary introduction of a different theology. The report makes much of the symbolism of the common cup. Jesus used one cup the argument goes and so should we. As far as we know Jesus and 12 disciples took part in the first communion. There's no escape from using more than one chalice where numbers are large and the report rather lamely suggests this waters down the symbolism. The problem with this argument, is that if you allow several cups for large numbers, it is harder to see the problem with the trays of small cups.
Furthermore, the argument from symbolism seems rather feeble to me. The report is trying to marry two (at least) theological systems. The problem is that Methodism and Anglicanism are different and over their years of separation have developed rather different approaches both to communion and the ways in which we do theology. I suspect the big cup has put in an appearance on communion tables because Methodist Ministers train with Anglicans and have taken on board the symbolism of the single cup. To Methodist lay people I suspect it is a confusion if they think about it at all.
There are many ways of symbolising unity and a common cup is one of them. Another is to hold onto the individual cup and all drink together. This would be a better symbol of unity in large gatherings than several larger cups.
Drinking together as a symbol of unity is how my church understands what it is doing. The 2003 report to Methodist Conference, His Presence Makes the Feast, clearly shows Methodists work out their theology together. In the Church of England liturgy is more centralised and mediated through the Bishops.
This chapter strongly implies there is one correct interpretation of communion. It is not acknowledged that Methodists might have their own understanding. Even if the report mentioned drinking together and then dismissed it, it would be better than not acknowledging it at all.
The report implies unity means we must give up our way for another way, which needs to be imposed from above. In the real world single congregation Local Ecumenical Partnerships do what makes sense to them. It is forbidden to celebrate with some using a common cup and alcohol whilst others use small cups with non-alcoholic wine. Guess what.