Today's news that the anger among legal aid solicitors has boiled over to a threatened mass walk-out is no surprise, representing the climax to months of frustration and fury.

Lord Falconer of Thoroton's plans to overhaul the £2 billion legal aid scheme have been condemned from the start.

The solicitors' message is a hard one to sell, looking like professional self-interest and a wish to preserve what the public assume are rich pickings.

In truth the legal aid scheme is colloquially "on its uppers"; and those lawyers still in the business scrape a modest living.

Once a lucrative gravy train, ministers have in recent years "borne down hard", in the words of one Lord Chancellor, on legal aid. Many of the excesses have been squeezed out and fees held down for successive years.

So the latest planned overhaul, arising from Lord Carter of Coles' review, comes on top of a system already creaking at the seams.

Some reform is needed. The system is still hugely inefficient and costly to run with many thousands of firms, often with small offices, providing services. Many of the inefficiencies, though, arise from the poorly-managed criminal courts.

Because of the low rates of pay, there is a also dearth of new entrants. So the future of the scheme is at risk, with an ageing profile for the typical legal aid lawyer.

There are, as well, a few so-called "high cost" cases which eat up almost half the legal aid crown court budget. It is these cases which give rise to the stories of £1 million a year earnings on legal aid.

That, Lord Carter said, had to end. So he proposed a market-based system, which will reward economies of scale. Firms will compete for legal aid contracts through competitive tendering; and fees will be fixed.

The big super-legal aid firms will win out; hundreds, by the Government's own estimates, of small offices will close, or merge.

It is the model of the supermarket versus the High Street. By that same token, there is the same argument that accessibility will go, that rural areas will lose their access to lawyers.

But this is about more than size versus spread: lawyers say that the lack of small firms will mean no solicitor present to deal with emergency injunctions when a wife or child is a victim of domestic violence; or to advise when someone is being thrown out of his or her home.

And, they argue, Lord Carter's model is flawed. The big efficient firms, or perhaps one or two small specialist niche firms, will win the contract in their locality.

The other firms in the area will go to the wall. When the contract comes up again for tender in three years' time, who will be left to pitch for it? No-one, but the same winning firm. The system of competitive tendering will collapse.

There are criticisms, too, of the system of moving lawyers on to fixed-price contracts. The Lord Chancellor's wish to end the system of "payment by the hour" is justifiable.

But are the proposed fixed fees too crude, failing to reflect the particular complexities of work with children or mental health?

The concerns are shared. At least 20 leading charities are backing the Law Society in its campaign over the plans and senior judges, too, have warned of the impact in areas such as child care law.

They have called on the Lord Chancellor at the very least to scrap his timetable and give more time for fine-tuning: so that the fees for child care lawyers, for example, reflect the complexity of cases.

Lord Falconer has made a series of concessions and altered, slightly, his original timetable. But he insists there is no more money. All changes must be "within the envelope." And the signs are that far from appeasing his critics, their anger continues to mount.

The Lord Chancellor clearly has very little room for manoeuvre. Whatever action solicitors take next week, in reality their best hope will be to secure a breathing space, by lobbying the growing number of MPs, as well as judges, who are on their side.

With the public sector strapped for cash, they will not save the legal aid scheme in its present form. The question, though, is whether these proposals will see the survival of a legal aid scheme in any shape at all.

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