The cabinet is meeting for possibly the last time before a general election is called, according to news reports. But how will the BBC tackle the campaign and how does it remain impartial?
There's more to achieving fairness than just covering the "big three"
For decent coverage of politics, the idea of "balance" is not enough.
It is a starting point but the true, and far more testing, notion is fairness.
Balance can sound almost numerical, and during election campaigns in particular, the party headquarters do use stop-watches, or digital timers, so that they can complain to the BBC if we fail to give exactly the quota of airtime we promised.
That quota is based on their electoral performance and popularity: it would not be balanced to give Robert Kilroy-Silk's Veritas party the same amount of airtime as Labour, or UKIP the same size of shout as the Conservatives.
Knowing that one is obliged to give airtime to different parties is an important discipline, and we don't knock it.
But of course when it comes to fairness, that barely gets us to first base.
For a start, how do you balance different views inside parties?
It would be an abuse of our position if we kept dissenters off the air - they have a right to be heard.
Yet to make TV news packages in which the Labour voices were Bob Marshall-Andrews, Dennis Skinner and Clare Short would not be balanced.
It would be downright unfair to the Labour government.
So, at the back of my head, I try to ensure that the main voices speaking in "Labour airtime" or "Tory airtime" really do represent the leading strand of thinking in those parties, while also ensuring that dissenting voices get a show, from time to time, too.
This can mean, between elections, that a political film is balanced even if all the contributors are from the same party - you could do a fair piece about Labour's agonies over the Iraq war without a single Tory or Liberal Democrat voice.
Ditto a piece about a Tory leadership struggle - putting a Labour voice into the mix to jeer from the sidelines is virtually pointless.
As the election approaches, however, this kind of one-party-balanced story becomes steadily less possible, because people are confronted by looming party choices.
Yet it is very easy to balance our coverage immaculately and still be grossly unfair.
By choosing this sentence or that from prime minister's questions, I can make Tony Blair, Michael Howard, Charles Kennedy or anyone else look bumbling, irrelevant, tetchy... or rather brilliant.
Balancing views within parties can be just as hard as those outside
The rule of thumb is that, to give viewers and listeners the best sense of the real arguments, you look for the best points made by different people or parties, expressed as vividly and clearly as possible.
Why? Because that is where the argument and the difference is sharpest.
Howard at his best exposes Blair most effectively; and vice-versa.
Politicians know very well when journalists have highlighted a less successful piece of their argument, and rightly wonder if it's a subtle attempt to do them down.
The coming election introduces yet another dilemma.
In the South-west of England, the Lib-Dems and the Tories are fighting each other in many seats where Labour is barely in contention.
In parts of the north of England, the same is true of Labour and the Lib-Dems.
Scotland and Wales, never mind Northern Ireland, will have campaigns which are more distinct from the fight in southern England, or the English Midlands, than ever.
So how many "general" elections will there be? No longer can we just focus on two big parties, one smaller one, and leave it at that.
In the end, we are a nation, with a national choice, and the BBC is the national broadcaster.
But balance, not to say fairness, will mean that we have to look at specific parts of the UK more closely than ever before.
If that sounds complicated, the European constitutional referendum, assuming it takes place, will be even harder.
Individual parties are split. The "yes" campaign will be united in calling for a single outcome - the EU constitution ratified.
But the "no" campaign will include a range of opinions, from people who are not happy with this particular constitution, to people who believe our national interest requires leaving the EU as soon as practicable.
Fairness, or balance, will involve explaining this without implying the "no" campaign is incoherent, simply because it is divided on the ultimate outcome.
Finally, however, fairness is about trust.
If you believe that I and my colleagues at the BBC are honestly and rigorously trying our level best to be fair, and that we do not have preconceived political positions, then you will be likelier to relax and concentrate on the information, not the informant.
We don't get it right always: there are difficult judgements to make, sometimes about tiny verbal nuances, every single day.
But we do try - and we will.