The Glasgow Bar Association (GBA) voted unanimously for industrial action at a meeting in the city's sheriff court.
Hundreds of lawyers are now poised to take part in a strike that is likely to throw the court system into chaos.
The result follows an earlier move by the Edinburgh Bar Association in response to a dispute with the Scottish Government and the Scottish Legal Aid Board (Slab).
The Government has proposed that those accused of a crime who have a disposable income of £68 a week or more should make a financial contribution to their legal aid.
Solicitors will be asked to collect contributions from clients in summary (non-jury) cases instead of getting the whole fee from Slab.
However, lawyers say this will turn them into state-sponsored debt collectors and damage relationships with clients.
They fear payment issues may also cause court delays and lawyers could be left out of pocket by up to £485 a case if clients do not pay.
Bernadette Baxter, president of the GBA, said: "Our major concern is that solicitors are being asked to collect these payments in summary cases, which make up the vast majority of cases.
"But we're also angry this has all been considered by the Justice Committee, who recommended the Government reconsider the issue, and the Justice Minister has run roughshod over the democratic process and pressed ahead with it.
"It's completely inappropriate the burden of collection has been placed on the profession. "
The Government plans form part of the Scottish Civil Justice Council and Criminal Legal Assistance Bill, which is going through Parliament. The bar associations insist they will strike if it passes the second stage of the process next week.
Other Scottish solicitors are also expected to join in should industrial action go ahead.
Labour and the Tories have given the solicitors their backing. The Law Society of Scotland has also been pushing for the Bill to be amended.
Law Society of Scotland legal aid convener Oliver Adair said: "We have presented compelling evidence to the Scottish Government and to the Scottish Parliament that Slab is the body best equipped to collect criminal legal aid contributions.
Slab says it is "not well placed" to collect the large number of smaller contributions due in summary cases.
A Scottish Government spokesman said: "Getting Slab to collect all contributions would reduce the level of savings to the taxpayers' purse that could be achieved from these proposals and would be impractical. Solicitors are much better placed to collect the relatively small contributions involved in most summary cases."