Make no mistake about it. Whatever your politics, UKIP's manifesto is truly impressive. And at its unveiling today, it was even more impressive that the manifesto's lead-author, party Deputy Chair Suzanne Evans, managed to outshine Nigel Farage.

UKIP thus slew two dragons with one blow: it's not a one person party -- Nigel may have a potential successor, should the need arise; and it's definitely not looking like a one trick pony.

As Ms. Evans said towards the end of her speech: "I think I've already covered quite a lot of ground for a single issue party".

And so she had.

Highlights included plans to repeal the Climate Change Act; slashing the wasteful foreign aid budget to 0.2 percent of GDP (the same level as in the U.S.); powers of recall and plans to let the people have a referendum on any issue of their choice; pledges for a fairer and saner immigration policy; obviously a referendum on EU membership; and a firm promise to keep the proportion of GDP spent on defence at the NATO-recommended level of 2 percent.

UKIP is still hugely disadvantaged by the unfit-for-purpose first-past-the-post electoral system. But if they can keep up the momentum, they could pose a bigger threat than ever to the Conservatives.

It is vital, therefore, that the Tories now raise their game. And with that in mind will someone at Conservative headquarters have the guts to ask the following question: How on earth did the Tories get outflanked by UKIP on defence?

For decades, the one thing that everyone could agree on was that the Conservative Party was the natural home for anyone who put defence of the nation at the top of their priorities.

How difficult could it be for David Cameron to guarantee that a Conservative government would meet that most basic minimum recommendation from NATO?

The mind boggles. And it will boggle a lot more if the challange that UKIP threw down today is not taken up and met robustly.

Are the Conservatives up to the task? The answer will determine the outcome of the election.

p.s. The LibDems also launched their manifesto today. Did anyone notice?