Okay... a few hours left, but if someone could provide possible explanations for a sudden Labour landslide, I'm all ears (out of ideas here given the background)
Well Labour did win in a landslide in '66...
Of course, they had been able to put off devaluation until after that election, but the balance of payments crisis was truly severe when they came into office and they had an extremely tenuous majority of four (which quickly shuttled down to two). My point being, Wilson's ability to show that Labour could lead an effective government helped immensely.