This in the openlabour interview is nailed on:
"the results of elections are actually pretty incidental to actual political outcomes. Elections are important, but they’re not usually as important as people think they are. Broadly speaking governments in Britain from 1940 – when the war cabinet was formed – through to the 70s pursued a pretty consistent agenda and set of policies. That began to fall apart in the mid-1970s when the Callaghan government started to cut back on the public sector, weaken the unions, and so on. And since then – since the 1970s – that agenda has remained in place pretty consistently up until the present. On the basis of these examples you can say that what happens in elections is a symptom of underlying social forces, rather than being the absolute and determining factor in terms of outcomes. Elections determine who gets to be in government, but they don’t determine what those in power actually do.
I would say that actual political outcomes are, to use a Gramscian phrase, an expression of the balance of forces – they are an effect of the relative strength of different groups in society to influence outcomes and shape the agenda. Generally speaking, from the 40s to the 70s, the two strongest social constituents were manufacturers and the trade unions. Between them they more or less shaped most of the direction of social and economic policy. Since the 80s, the most powerful force in Britain and globally has been financial capital. So unless you can build up some social coalition which means you can organise things differently, then things aren’t going to fundamentally change, regardless of the results of the election. You’ve got to think about how the balance of forces can be shifted."