By Brian Taylor Political editor, BBC Scotland

Politics can have the hallmarks of tragedies like Macbeth

It tells of the relentless, brutal futility of life, at least as seen through the eyes of the doomed King whom actors supposedly decline to name, for fear of bad luck.

It has always struck me as being pertinent to political life.

There is a relentless element to the electoral cycle, particularly if you're struggling.

Whatever you say, whatever you do, the voters, blast them, appear intent on choosing the other lot.

Each passing day merely draws you closer to oblivion.

There is, of course, another line in the same speech which also calls politics to mind.

King M, who is having a decidedly bad heir day, likens life to "a tale told by an idiot, full of sound and fury, signifying nothing". Just your average Holyrood debate, then.

Enough, Brian, enough. Ditch the scholarly enthusiasms of your youth and get back to bald politics.

Here we are, another tomorrow, another month, another day nearer the Holyrood elections on May the third. But just where are we, politically?

The battle lines are being drawn for May's election

Strikes me we have yet to determine the agenda, let alone the outcome.

In particular, the largest parties, Labour and the SNP, are seeking to shackle their opponents in an agenda not of their own choosing.

Labour wants these elections to be a referendum on independence, the SNP's principal aim.

They want the voters to draw a single, simple line in their mind from the SNP to independence to risk to cost to tax.

Privately, Labour strategists say that mantra is already there in the electoral consciousness, at least according to focus group findings.

Many voters, it's said, are disquieted by the thought of independence or, more precisely, by the change and upheaval which it might entail.

Vaguely, they connect that with cost and, hence, with higher taxes.

Will Labour reinforce that message day and daily, tomorrow and tomorrow? You bet your electoral deposit they will.

Cathy Jamieson is spearheading Labour's Scottish campaign

There was a Roman politician, Cato the Censor, who used to pepper every speech, on whatever topic, with the demand: "Delenda est Carthago."

Carthage, he felt, must be destroyed.

Was the Senate debating sewerage? Cato would join in - then swiftly move on to the topic of Carthage, its annihilation.

But Cato was an amateur compared to Cathy Jamieson.

Every Labour news conference she chairs - on education, health or ferret-taming - instantly turns into a diatribe about the perils of independence.

By intriguing contrast, the SNP wants floating voters to consider independence to be a matter for another day.

That other day being the moment when an SNP-led government calls its referendum on the issue of repealing the Act of Union.

This is, quite consciously, an echo of Labour's tactics in the UK general election of 1997 when the party sought to stress that devolution would be determined by a subsequent referendum.

As in 1997, the strategy is partly justified and partly bogus.

Alex Salmond hopes to emerge as Scotland's first minister

Yes, the elections on 3 May are primarily about electing a devolved government to deal with devolved powers over schools, hospitals, the law.

But voting to give the SNP devolved power would be a substantial step towards independence and the electors are entitled to scrutinise the potential destination.

Rather, the Nationalists hope 3 May will be a referendum on Labour - or, more accurately, on Tony Blair, Iraq, cash for honours, UK issues.

They hope disgruntled voters will wreak revenge on the target in their sights, the Labour-led Scottish Executive.

So what else? Well, polls, including the latest ICM in The Scotsman, continue to suggest an SNP lead.

Cue furrowed brows in Labour ranks, as they strut and fret their hours upon the electoral stage.

But the lead is far from big enough to sweep the boards for Nationalism.

Even if sustained, the SNP would need a coalition buddy.

And the Liberal Democrats resolutely refuse to play while the Nationalists insist on THAT referendum.

The Lib Dems are pinning their hopes on leader Nicol Stephen

Then the Nationalists have devised a rather cute trick of registering a dozen names for their party, featuring references to local controversies and also branding their leader.

When you enter the polling station, you may face the option of "Alex Salmond for First Minister" on the regional vote.

In 2003, the SNP believe they neglected the regional or "second" vote. This time round, reforms mean no "second" vote.

The regional and constituency choices will be presented to voters on a single ballot paper - with the regional on the left hand side and thus, optically, first.

The SNP hope is that the regional vote will be seen as fully contributing to the choice of government. Hence Salmond FM.

But I stress again the election has yet to find a common battle-ground, let alone begin the contest for real.

For now, the two big parties arm-wrestle over the agenda.