Spare me please from politicians' tax returns.

Boris Johnson and Ken Livingstone locked antlers on the issue during a televised debate for the London Mayoral election. Suddenly we're up to our elbows in demands that all politicians make their tax affairs public.

George Osborne says he is happy to consider the proposal for ministers. (He can hardly refuse to consider it.) It's a preposterous idea. MPs' incomes are already declared. So are we saying we don't trust politicians to pay their fair share of tax unless their returns are also held up to public scrutiny? Must all be treated as cheats to guard us against the crooked? Or is something else behind this: a festering resentment that we're not all in this together; that a smug coterie at the top is coining it and looking after its own?

Mr Livingstone was suggesting the latter. He was aligning his own mayoral candidacy with the lot of the common man. He was pointing at Tory toff Mr Johnson's sky-high earnings and implying he supported a cut in the 50p tax rate for personal gain.

What was revealed along the way was Mr Livingstone's own interesting devices for minimising tax. They have to do with being paid through a company. He justifies the arrangement by saying he employs three people – one of whom is his wife.

It's labyrinthine. It's boring (at least to me). I have one concern about them both – and more importantly about ministers, MPs and MSPs. Are they living within the law? If they are, their income tax arrangements are none of my business. If they are not, throw the book at them.

If, somewhere between, they are acting within the letter of the law but not its spirit, adapt the law. Tighten restrictions. Plug loop-holes. But please don't publish the minutiae of their private financial affairs. They will tell us little or nothing.

Two people with similar incomes can legitimately pay different amounts of tax. One could pay less tax because he or she makes bigger pension contributions than the other. One could pay tax on savings income; the other might have invested in tax-free cash ISAs. Doesn't the Government encourage us all to save and sweeten the pill with a tax incentive?

Take another example: a Government Minister could be paying the same tax as his colleagues, but have transferred a property portfolio into a spouse's name. The tax liability would also shift. Knowing the Minister's tax affairs wouldn't disclose his or her family's wealth or tax arrangements.

There's nothing illegal or wrong with this but Mr Livingstone is already demanding that mayoral candidates reveal household income and tax.

It's an invasion of privacy – especially in a society where two-income families are the norm. Why should a family's private financial affairs become public knowledge just because one person enters public service?

I value privacy. I want our elected representatives to guard our right to it. Will they be inclined to do so if every last detail of their own private financial affairs is forcibly published? If household wealth and tax are to become public, who will want their spouse to enter public life? It's a slippery slope.

Already there are calls for it at the BBC. How long will it be before senior civil servants and all who hold senior posts in the public sector are included? It's a snoopers' charter as well as a way of legitimising envy.

It does us no good to be reminded how others can command incomes which are multiples of our own. There isn't a journalist in Scotland (and very few in the UK) who won't have winced when they heard Mr Johnson is paid £250,000 for his London newspaper column.

The generous spirited will take their hats off to him. Begrudgery is the fate of the rest. It will damage them, distract them from building their own prosperity and do Mr Johnson no harm.

Do high earnings disqualify him for public office? No. Should they? No.

We are being invited to be chippy. We are encouraged to see ourselves as a downtrodden "us" being ruled by gravy train "them". But we are not living in pre-revolutionary France. If that's what we really think about those who are in power, let's throw them out at the next election.

But let's not diminish ourselves by setting up an atmosphere where the qualifications for public office are a childhood without shoes combined with low adult earning power. It would be as unjust and ineffective as insisting that every senior politician had to have a private education and have independent means.

It must be better to judge each candidate on their merits, on their judgment and probity but, most of all, on their effectiveness.

We can insist a parliamentary scrutiny committee has access to all of their personal accounting. And – having learned the lessons of the expenses scandal – let that committee itself be scrutinised so that it is known to be fierce. But let's avoid the route of publicising tax returns.

Anyway there are other fatter geese to pluck than politicians. Why pursue ministers when giants like Apple and Amazon slide away tax free in the UK – or as good as. Apple is reported to have paid £10 million in tax on an estimated UK turnover of £6 billion. Amazon pays no tax in Britain despite turnover of £7.6bn over three years.

I believe in a meritocracy. I couldn't care less whether those at the front in politics are black, white or brown, rich or poor. What matters most is that they run the country well.

It matters more than ever since the credit crunch. The economic balance of power is shifting east. If we are to reclaim prosperity, encourage wealth creation and ensure a brighter future for our children we need our best talent to the fore. Instead of bickering about the social origins, personal assets and tax bills of our leaders we should focus on what they achieve for us. But unless or until they break the law, let their private tax affairs remain just that.