The recent rally by Justice for All brought to the heart of Westminster the concerns of a coalition of organisations about the Conservative-led government’s proposed cuts to the legal aid budget.

For more than 60 years, legal aid has performed a critical yet unassuming role in providing support to those most at risk of being excluded from our legal system. Its creation was a recognition by the state that the government has a duty to ensure all citizens gain access to the courts system regardless of a shortage of finance – fundamental to ensuring the principle of equality before the law is upheld.

Clement Attlee’s radical reforming government saw the Access to Justice Act (1948) as a central plank in the construction of a post-war welfare state, along with national insurance, the NHS and education reforms. But the world of 2010 is transformed beyond recognition from that of the 1940s. The needs of the individual have changed, the legal system has evolved and the taxpayer is more stretched than ever before.

While the state continues to have a duty to ensure, as far as possible, access to justice is met without recourse to public funds, there will always be a need that cannot be satisfied without some form of state financial support. This leads to a tension over the exact level of taxpayer involvement in guaranteeing access to justice.

Kenneth Clarke’s solution is to slice £350m from the legal aid budget – and civil legal aid will shoulder the majority of these cuts. As a result, more than 500,000 people will no longer be eligible for legal aid. It is social welfare law that will take the biggest hit, meaning all of welfare benefit issues, employment law and education law will now be out of the scope of legal aid.

Perhaps the most alarming figure is that 68% of civil legal aid – the kind for initial help and advice on legal problems – is to be cut. Practically all debt advice and a large part of housing law will no longer be eligible. This is simply irresponsible in the current economic climate, at a time when many people will be in need of early stage guidance and support. Without early legal advice in these areas – which can be complex even for experienced legal brains – there is the risk of problems escalating.

The public purse will be hit by wider social and economic costs further down the line as a result of the snowballing of these kinds of issues. Research by the Citizens Advice Bureau (CAB) shows that every £1 of legal aid expenditure on housing, debt, benefits and employment advice potentially saves the state £2.34, £2.98, £8.80 and £7.13 respectively. What might appear to be a saving for taxpayers is nothing more than a displacement of costs elsewhere in the public sector.

The proposed cuts will also slash £50m from the CAB and law centres network. For these invaluable institutions, this is a triple-whammy: they will be swamped with additional inquiries from those left high and dry by the green paper’s cuts, at a time when there is enormous pressure on other funding sources and when the economic conditions mean a rise in issues such as debt and housing problems. Many CABs and law centres will simply have to close their doors. I know through the experiences of the South West London Law Centre, in my constituency of Tooting, that there are serious concerns about future funding.

This is one area in which the pain of the coalition’s cuts will not be equally shared. Our society’s most vulnerable are disproportionately affected and evidence suggests ethnic communities and people with disabilities will be most affected by these cuts.

We also harbour anxiety about the proposals to rely more on a telephone-advice service. This simply will not be an adequate replacement for valuable face-to-face interaction, nor will it be suitable for those with social and language barriers to deal on the telephone with complex and lengthy legal matters.

I firmly believe in controlling legal aid costs to maintain its integrity and effectiveness. But our starting point has always been that legal aid needs to stay focused on providing support in those areas necessary to avoid critical aspects of the legal system becoming out of reach of the most vulnerable in society. That’s precisely why it is right and proper to periodically review how the system is operating – and that’s why we take a different approach to the Conservative-led government in this respect.

I would like to pay tribute to Lord Bach for the work he did in government to defend social welfare law from cuts. We would have carried on explicitly to do all we can to protect social welfare law and thus shield the most vulnerable. The Labour government’s March 2010 proposals, had they been implemented, would have led to 10% efficiency savings, which would have stemmed from improving the way legal services are contracted from solicitors – the aim was to have fewer providers supplying more volume at less cost to government. The coalition has rejected this option, instead delaying any consideration of competitive tendering until 2011.

By implementing this outstanding policy recommendation, our proposals would have protected social welfare legal advice and helped avoid the legal advice deserts the coalition’s proposals will create.

We agree savings need to be made. We had started that process. But we disagree fundamentally with the route chosen by this government. By decimating social welfare legal advice the coalition seems intent on destroying a system that was created to change lives for the better.

The government is currently consulting on its proposals and I would urge everybody with a stake in our justice system to make their views known. It is imperative those who believe in the principles of legal aid and who have seen its financial and social benefits make their voices heard.

The Rt. Hon Sadiq Khan MP is shadow lord chancellor and shadow secretary of state for justice and constitutional affairs