Labour or Liberal they will win or lose the next election on...

Labour or Liberal they will win or lose the next election on their Energy Policy.
The three imperatives which any credible energy policy must answer to are security of supply, affordability and environmental responsibility.
There may not be many votes to win by quietly accepting the non-negotiable reality of that statement but there are certainly votes to lose by adopting policies which conflict with it.
A distinguishing political characteristic of energy policy is that for long periods, it may seem unimportant and then, suddenly, it becomes absolutely critical.
Any prospective party of government which neglects that risk does so at its peril, particularly in the run-up to an election!