A national advice charity has welcomed a report by MPs, which warns the most vulnerable people could be hardest hit by cuts to the legal aid budget.
MPs warned today that this may lead to "advice deserts" in some areas of the country.
The Commons Justice Select Committee said the Government had not worked out the full impact of the reforms on the disabled and black and ethnic minority communities.
"While it is taking some steps to address those gaps, evidence we have received, and the Government's own thinking, suggest that these people, as well as other vulnerable groups, rely more on legal aid services than do the less vulnerable, and so there is the potential for them to be disproportionately hit by the changes," the cross-party committee said.
"If this were to happen it would sit uneasily with the Government's commitment to protect the most vulnerable in society."
Plans to cut the £2.2 billion-a-year legal aid budget by £350 million are expected to cost 500,000 instances of legal assistance and 45,000 representations each year.
Gillian Guy, Citizens Advice chief executive, said: "We welcome this report, which clearly recognises that the Ministry of Justice has provided insufficient evidence to justify proceeding with massive changes to the scope of civil legal aid without having fully considered all the options for reducing costs and preserving crucial areas of advice.
"The committee shares our concerns that the Ministry of Justice's proposals sit uneasily with the Government's commitment to protect the most vulnerable in society.
"It also recognises that - as we have made clear - the proposals could mean an uncertain future for the sustainability of not-for-profit advice providers.
"Every year thousands of our clients need help from civil legal aid services at moments of real need. Withdrawal of legal aid for social welfare advice with no alternative on offer will leave the most vulnerable overwhelmed by problems with nowhere to turn.
"We would urge the ministry to undertake further work to scope out legal and procedural reforms which could improve efficiency, reduce costs and save frontline services."
She said solutions "can be found which will fulfil the ministry's objective to deliver a less costly and bureaucratic system" yet continue to allow people to "be empowered to access their rights".
She added: "The ministry is making far-reaching reforms to the civil justice system which should be judged by whether they increase access to justice. We fear that the combined effect of proposed reforms to legal aid and legal costs could have the opposite effect."
Last year more than 300 specialist Citizens Advice Bureau case workers - paid for by legal aid funding in social welfare law - dealt with more than 40,000 welfare benefit cases, almost 60,000 debt cases, over 9,000 housing case and 3,000 employment cases, accounting for over 20% of all publicly funded cases in these topic areas.
A Ministry of Justice spokeswoman said the select committee acknowledged the current system was one of the most costly in the world and was in need of change.
She said the Government's reforms aimed to move towards a "simpler justice system", including one where people could resolve issues out of court, using "simpler, more informal remedies" where appropriate.
Law Society president Linda Lee said: "This report, coming as it does from an independent, cross-party source, is a valuable addition to wide range of voices expressing concern about the way this Government is proposing to make savings from the legal aid budget. The Committee shares our grave concerns about the lack of hard data underpinning the proposals and the lack of reliable forecasting of the potentially devastating effects. The Society was troubled by the committee’s conclusions in a number of areas. For example, the recommendation on education disputes could, if implemented, mean that ordinary citizens will be powerless to confront local authorities who fail to follow the law. If the Government will not provide remedy to secure rights denied, why bother with the right at all?
"We warmly welcome the Committee’s support for the Society’s proposed alternative savings and for other measures we have put forward to try and tackle the drivers of legal aid costs at source. We now urge the Government to heed the Committee’s concerns and to think again about how to meet the Treasury’s tough demands."
She spoke out as the Society launched a campaign to gather public dissent against the proposed reforms.
Impressionist Alistair McGowan has recorded an answering machine message in the style of Justice Secretary Ken Clarke for people to respond to.
The "Sound Off For Justice" initiative can be accessed via the campaign's website at http://www.soundoffforjustice.org.
Michael Mansfield QC - who is among a number of high-profile backers to have recorded messages - said: "How can people be empowered to enforce their rights if they don't have access to the courts for employment, housing benefit and so on?
"There'll be no service once these cuts come in. People should join Sound Off For Justice's campaign for alternative reforms, that will mean savings can be made but without jeopardising access to justice."
The Citizens Advice service comprises a network of local bureaux, all of which are independent charities, and national charity Citizens Advice. See http://www.citizensadvice.org.uk for more information.