The Edinburgh Bar Association (EBA) has already decided "overwhelmingly" in favour of industrial action, while the Glasgow Bar Association (GBA) and other organisations are expected to vote on the issue this week.
It comes as doctors in Scotland begin to vote on whether they are willing to strike over changes to pensions. Workers on ferry services connecting Orkney and Shetland to the mainland are also to be balloted over industrial action following the introduction of a new flexible working contract.
If the lawyers' strike action goes ahead, it will cause widespread disruption to justice of the peace, sheriff and high courts, with long delays to cases.
The Scottish Government has proposed that accused people who have a disposable income of £68 a week must make a financial contribution to their legal aid.
Solicitors will be asked to collect the contributions from their clients in summary (non-jury) cases – instead of receiving the whole fee from the Scottish Legal Aid Board (Slab). But they argue they will be left out of pocket if clients do not pay up. The Bar associations and the Law Society of Scotland believe Slab should be collecting the fees, as the board has agreed to do in solemn (jury) cases.
The plans form part of the Scottish Civil Justice Council and Criminal Legal Assistance Bill, which is going through Parliament, and lawyers insist they will go on strike if it passes the second stage of the process on November 13.
Mark Harrower, EBA vice-president, said: "The reality is this is yet another cut to our legal aid fee and we have had enough. Someone is going to be left out of pocket and Slab are trying to make sure it's not them.
"We've tried to negotiate with Slab, but now all we've got left is the right to withdraw our labour. If we do that, then every court in the capital will grind to a halt.
"If the GBA vote for strike action, which I believe they will, then that will leave two of Scotland's biggest cities in the same position. I've also spoken to lawyers up and down the country and no-one is happy about the Bill, so the industrial action could spread across the whole of Scotland."
Solicitors claim they will become unpaid debt collectors, while they have no power to sanction anyone who refuses to pay. They also argue it will damage relationships with their clients as they chase them for money while trying to represent them. Clients may also avoid returning to a solicitor they owe money to if they reoffend.
Mr Harrower added that despite solicitors, the Law Society and other legal bodies calling for Slab to make the collections, Justice Secretary Kenny MacAskill has refused to listen. Mr Harrower said: "In the consultation process on this Bill, almost everyone involved said Slab should make the collections and the Justice Committee agreed with this in its report. But Kenny MacAskill has chosen to ignore this and instead listen to the chief executive of Slab.
"He has a shown complete disregard for the democratic process. This move could leave solicitors out of pocket by anything up to the full standard fee of £485 in each summary case, depending on what the client's disposable income is. We're not asking for a rise, we're asking not to be subjected to another round of cuts."
Solicitors staged a one-day strike in 2008 over proposals to cut the legal aid bill by £3.9 million with long-running plans to reform the system which costs the taxpayer around £161m a year.
Oliver Adair, the Law Society of Scotland's legal aid convener, said: "We understand the profession's frustrations, which we share, as the Scottish Government does not recognise the validity of our arguments in relation to the collection of contributions."
A Slab spokesman said: "The board believes solicitors are better placed to collect contributions towards their fees from their clients in summary cases.
"The board does collect contributions in civil legal aid, and the Bill provides it will also collect contributions in solemn and appeal cases. However, it is not well placed to collect the larger number of much smaller contributions due in summary cases. Any move away from the provisions of the Bill will lead to additional cost to the taxpayer."
A Scottish Government spokesman said: "The Scottish Civil Justice Council and Criminal Legal Assistance Bill proposes to introduce contributions to criminal legal aid, bringing it in line with civil legal aid. The principle is that those who can afford to contribute should do so.
"The proposals have been positively received, including by the Law Society, and will not compromise access to justice."