Labour's Stance on Energy Prices - Do Policies matter in shaping Voting Behaviour?

How significant are policies in voting behaviour?

I read in article by Andy Beckett (link below) in the Guardian recently and it made me think about what the implications would be in terms of voting behaviour with regards to Keir Starmer's recent announcement on energy prices. (For details of the policy announcement see here.) Beckett argues that after a coupe of years of lagging behind the Conservatives, the cost of domestic energy might be a pivot around which Labour can build momentum heading into the next election.

The modern electorate, as probably all Politics students are aware, are inclined to cast their vote according the rational choice model. The twin anchors of partisan and class alignment still heavily shape decisions by voters at the polls, but they don't decide the outcome. It is decisions by the vital swing voters that ultimately determine what the colour of the door at Number 10 will be painted.

As such, it is the 3Ps that matter: past performance, the party leader, and future policies. (We could add a fourth 'P' here for party unity). And so, as things stand, it doesn't look too good for the Conservatives, who according to some polling are 16 points behind Labour (even a poll of polls gives Labour a double digit lead).

Read the article, and decide how significant this policy might be in shaping voting intentions.