On Budget day morning, we would all do well to examine what Polly Toynbee wrote in The Guardian yesterday.

I can think of many occasions when my opinion has differed diametrically from that of Guardian stalwart Polly Toynbee; but her piece yesterday emanated such sound sense, practical ethics and creative ideas, it added to my growing belief that Left and Right need to be ditched in favour of Right and Wrong. Despite relativists insisting that Right and Wrong as concepts are both naive and dangerous, I return as always to the G K Chesterton adage of nigh on a century ago: ‘People only invent new values because they can no longer live up to the old ones’.

It is oh so easy to be triumphalist in the context of four Labour MPs (three of whom are ex-Ministers) being caught in the act of nefarious activity. But most fair observers know perfectly well that a better choice of Tory MPs by the sting’s organisers would have produced a similar result among Opposition MPs. Indeed, only libel laws stop me from naming five right off the bat.

But Toynbee’s extrapolation from this mess was pure genius: the lobbying scandal has created, she wrote, a challenge to both major Parties. Darling now has the opportunity in today’s Budget to show he stands for that fairness lying at the core of the traditional Labour Party. This would in turn, Polly suggested, challenge Cameroonian Conservatism to live up to its newly-minted fairness claim.

Her central point was the innate unfairness of the current tax system. Why, Ms Toynbee asked, do the poorest 10% pay 46% in tax, while the top 10% pay only 34%? Very good question unless you’re a Friedmanite – and I’m not. Especially as quite a few in that top 10% (either through weak acceptance or actively insane behaviour) got us into the mess we’re now in.

Actually, although miles to the Right of Polly Toynbee on the old directionally described politics, I’d be far more radical than her on the tax issue. First, I’d ensure that all those commercial concerns getting away with obscenely unfair tax avoidance were made to cough up in a manner more befitting their massive access to our consumers. Second, I’d slam down hard on inherited wealth – because nearly every inheritor of a fortune I’ve ever met has been a drug-fuelled waster, and I regard unearned privilege as a major fault in our society’s rules of engagement. But above all, I would abolish income tax, and base any future taxes on social behaviour.

But all this is beside the main point. In recognising the need for frugality and fairness, Polly’s piece sets (for me anyway) a moral agenda that is both practical and just. If lazy buggers are to go without, then it seems to me iniquitous that the innocently stretched majority should suffer far more genuine pain than that economic group which has benefitted most from the last thirty years.

Toynbee, of course – like James Purnell – is after the rekindling of that Labour soul so easily sacrificed on the altar of Blairite spin. For myself, I will always fear that the Left’s dependence on loud-mouthed and undemocratic trade union bullies will get in the way – as equally, I know from experience that privileged money drives too much of any Tory agenda. I would make all ex-Government donations to political Parties illegal, and make it a matter for accountants and psephologists to decide funding based on unimpeachable calculation rather grubby interest groups. We have a truly objective beacon in the Office of National Statistics. What we need is an Office of Party Funding. I loathe most quangos, but this one is a must-have.

But all that change lies in a future which must inevitably (and painfully) come to pass. For now, Polly Toynbee has challenged the political class in a way only rarely managed these days.

‘This Budget’ she wrote, ‘should challenge David Cameron to match Labour on fairness’. It won’t – any more than the Opposition leader would truly want to match it if it did. Toynbee’s challenge is right on the money, but the existing Party system will never step up to it.

This may be where we differ, but it doesn’t matter: in the long term, my feeling remains ‘Thank God for Polly Toynbee’.