I think there may have been some misunderstanding about what I've been saying.It is still voluntary, no company is insisting that you must have a SM, even if some are saying to get certain tariffs, then you must have a SM. You still have the option, not to take the tariff.
What you say above is, as far as I am aware, currently true. Government certainly has not introduced any 'compulsion' and, again as far as I am aware, no supplier is currently forcing any consumer to have a 'smart' meter.
My point has been that, even in the absence of any government-imposed compulsion, some (maybe all) suppliers probably have a contractual right to 'force' SMs onto anyone who wants to use their electricity supply, if/when they wished (not yet) to exercise that right. Just as they currently do not offer particular tariffs to customers without SMs, so they could presumably not offer ANY tariff those those without SMs.
Just as, as a final resort, they will cut off the supply from someone defaulting on their contractual obligation to pay for the electricity they use, so they probably could do the same with customers defaulting on their contractual obligation to allow the supplier to install "any metering equipment".
As above, it hasn't happened yet (hasn't yet needed to happen), since suppliers have, in general, been finding enough customers prepared to have SMs to enable them to meet the government targets and hence avoid financial penalties. However, that could well eventually change, when they have installed SMs for most of the 'agreeable' customers.
I suppose the bottom line of what I'm suggesting is that although it is currently possible to 'put off' having a 'smart' meter, the time will probably eventually come when having such a meter becomes essentially unavoidable.

