Edinburgh and Glasgow bar associations have voted to take industrial action in response to Government plans to force them to collect legal aid contributions from their clients.
The Faculty of Procurators of Dumfries has backed their decision and other lawyers throughout the country are expected to join any strike action in a move that could halt Scotland's court system.
Scores of solicitors are also expected to protest at the Parliament on Tuesday as the plans reach stage two of the parliamentary process.
Oliver Adair, the Law Society's legal aid convener, said: "We fully sympathise with colleagues in the Edinburgh Bar Association and Glasgow Bar Association who have taken such a vocal stand on this issue during the course of this week."
The Government proposals form part of the Scottish Civil Justice Council and Criminal Legal Assistance Bill which is going through Parliament. It proposes that those accused of a crime who have a disposable income of £68 a week or more should make a contribution to their legal aid and that this should be collected by solicitors.
However, the lawyers claim this would turn them into state-sponsored debt collectors and argue the Scottish Legal Aid Board is best placed to collect the money.