I can't argue with a lot of that Book but ultimately the unions behaved in such a way that the electorate found the Labour party to be unelectable.

It doesn't matter one jot whether the voters were right in that because the perception was there and the leaders of the unions behaved in such a way that the victory of MT was assured.

If the unions had behaved differently there wouldn't have been the climate for MT to carry out her policies, assuming that she had even been elected into office.