For non-Brits: here in the UK, political parties aren't allowed to buy TV or radio adverts. Instead in the run-up to an election they each get assigned a small number of timeslots (the amount depending on how major the party is) on the basic terrestrial channels for a short, well, one-off advert. They tend to make up for their lack of airtime by bombarding everyone with leaflets.
Anyway, Labour say "The NHS is doomed and it's all the Tories' fault". Only you can save the NHS!... by voting for us. They also can't decide whether they want a party political broadcast, or behind-the-scenes footage of a party political broadcast.
The Conservatives say "Work hard, put a bit aside for a rainy day, and everything will be fine" (isn't that the American Dream?). In slow motion. Oh, and don't forget that Labour will doom us all.
The Lib Dems are on the radio explaining how "No-one's going to win, so you need us to make sure no-one wins". And remember to look both ways when crossing the road.
UKIP say "I'm an ordinary bloke"... and waffle about how if you vote for them it'll cause a political earthquake. They're staying very quiet about the fruitcakes, loonies, and closet racists.
The Greens say "We're not a wasted vote, honest". Followed by... the Tories at the piano serenading the other parties in an glitzy boy band pop music video. Apparently it's been the number 1 hit for the past 200 years.
The SNP use a road trip to tell us that, deep down, they really do care. About Scotland. Oh, and didn't you know there's an election coming up?
Plaid Cymru explain that it's time to come out of the closet and vote for them, so you can finally be happy and stop having to hide who you really support.
Well, the Greens have easily won the video competition. None of the others are even close to the madness that is the Tories, Labour, Lib Dems, and UKIP singing "It's sweeter, when we all agree, a party political harmony~".