The Legal Action Group (LAG) and the Law Society are asking the Lord Chancellor's Department (LCD) to think again over its proposal to remove criminal advice and assistance from the scope of the green form scheme.
They say that it could leave a significant number of people without much-needed advice and assistance.
The LCD, which announced the plan in December, argues that duty solicitor schemes and criminal legal aid offer sufficient opportunity for free legal advice.
But both the LAG and the Law Society stress that the green form scheme is used to cover situations where other forms of assistance are not available.
In a letter to the LCD, LAG policy officer Vicki Chapman said that the proposal could lead to a denial of advice and assistance, delays in the administration of justice and a considerable increase in the workload of duty solicitors.
She added: “The result could be that, overall, there are no financial savings, simply displaced cost.”
The LAG is also concerned about the lack of consultation over the proposal. Chapman said: “The decision to raise green form abolition only with the Law Society and the Legal Aid Board suggests that the LCD considers this to be a matter of concern to providers of legal services rather than their clients.”
David Hartley, professional policy executive at the Law Society, said the society's response, issued last week, was designed to “rebut any suggestion that the Green Form scheme should be removed for criminal cases”.
He added: “We explain in detail what the Green Form is used for in criminal cases because its uses are many and varied.
“It is hard to see how most cases can be provided other than through the green form scheme.”
The Legal Aid Practitioners Group said it is also “very unhappy” about the proposals.