The Department of Justice has said that administration costs and payment limits mean it is not possible to deduct unpaid court fines from social welfare benefits.
Minister for Justice Alan Shatter has said repeatedly that he intends to end the practice of sending people to prison for non-payment of fines.
He would prefer instead to deduct the money owed directly from wages and social welfare benefits.
About 8,300 were committed to prison for the non-payment of fines last year.
However proposed legislation published on Friday shows that money will only be deducted from wages or occupational pensions but not from benefits.
Instead, people with limited means, such as those on social welfare benefits, will either have an asset seized to the value of the fine, or be ordered to carry out community service in place of the fine.
In a statement today, the department said that the Government decided last October not to proceed with deductions against social welfare payments.
It said this was due to the cost of administering the deduction of fines, and because social welfare rules meant only around €2 a week could be deducted.
The planned law - the Fines (Payment and Recovery) Bill 2013 - offers judges three options that will make imprisonment for the non-payment of fines a last resort.
Under the new bill, those fined will have an option to pay the fine over 12 monthly instalments, but they will also have to pay an administration fee of up to 10%.
For those who do not pay the fine and are brought back before the courts, a judge will have three options.
They can make an attachment of earnings order to deduct the fine from the person's wages or occupational pension; make a recovery order whereby a receiver will seize assets to the value of the fine; or make a community service order.
Depending on a number of circumstances, this community service will range from 30 to 240 hours.
It is only when these options have failed that the judge will be permitted to sentence the person to imprisonment.
Depending on the amount of the fine, this sentence can be no more than a maximum of 30 days.
Groups representing the lower paid have welcomed the news that social welfare benefits will not be touched and that community service replaces imprisonment.
However, the option to pay by instalment was included in earlier legislation that has yet to be enacted.
Minister Shatter hopes to have the bill enacted by the end of this year, and hopes to have it operational by 2014.
Work is ongoing on developing the Courts Service computer system to enable the proposed changes to take effect.