One of the first things we found out about Gordon Brown's plans for the country was that he aims to give the police powers to detain people for much longer under new terrorism laws.

These sorts of measures and the ceaseless creation of new criminal offences (3,000 since Labour came to power) necessarily mean people need lawyers more than they did. But, unless there's a fundamental change in government plans, Brown's prime ministerial term could be marked by the destruction of one of the pillars of the welfare state - our legal aid system, which has hitherto been the best in the world and guaranteed the poor access to justice.

Implementation of the Carter Review of Legal Aid, a report published last month by the Constitutional Affairs Committee, contains stark warnings.

The report highlights the fragile position of solicitors who provide legal aid and warns of the possible catastrophic consequences of a move to fixed fees in advance of a system of competitive tendering. It summarises the proposed changes as a "breathtaking risk" and an abandonment of concern for quality in favour of quantity of cases delivered. It also views the changes as a contravention of the prohibition of indirect discrimination in the Race Relations Act 1976 because of the disproportionate risk of closure of firms controlled by black and ethnic minority solicitors.

Despite the uncompromising language of the report, the government appears not to be listening.

Lord Carter admitted that his proposals would lead to the closure of many firms but asserted that most legal aid solicitors' jobs would be retained as larger firms were created by mergers. Those of us on the ground know he is wrong.

I have been an equity partner in my firm, Christian Khan, for 22 years. In the past year it has, like many others, closed down its immigration/asylum and housing and community care departments and we are struggling to continue doing family, mental health and public law. A possible merger has failed. In the meantime, people leaving my firm are often not staying in legal aid but going to more secure, less stressful employment.

As the parliamentary report identifies, most firms doing this kind of work also do criminal legal aid work and the reductions proposed in the amount we are paid for this will also impact on our ability to do civil legal aid work.

Most firms are in a precarious financial position and mergers are not possible if there is no security for large overdrafts; profit margins may be as little as 1 per cent and are rarely higher than 5 per cent.

The government is right to be concerned at the increasing cost of legal aid but, as the select committee found, this is not across the board but in just two areas - criminal legal aid and childcare cases. Not enough work has been done to identify what is driving these costs up or in accepting that new laws may be to blame rather than lawyers.

The legal aid budget of about £2bn is a tiny proportion of government spending and overall expenditure has actually decreased slightly since 2003-2004.

The government has vilified legal aid lawyers but most are paid modestly and work long hours to help vulnerable, low paid people.

I believe that the result of the proposed changes will not only be the closure of many legal aid firms but also a drastic reduction in the number of jobs and consequently in the free legal services that are available.