The Stormont Assembly has backed a ban on politicians double-jobbing as MLAs and councillors from the election due next year.
A bill banning the practice, brought forward by independent unionist Dawn Purvis, will now proceed to the further consideration stage.
During the debate Sinn Fein's Alex Maskey announced he would be standing down as a councillor after 27 years.
At times, the debate on the bill became heated.
MLAs exchanged barbs about each others' council membership, attendance records and outside interests.
Sinn Fein, the SDLP and the Ulster Unionists supported Dawn Purvis's proposal, but the DUP and Alliance expressed deep scepticism.
They argued that political parties should themselves voluntarily phase out the holding of dual mandates, rather than legislating to ban the practice.
Although Ms Purvis's measure only deals with double-jobbing involving Stormont and the councils, the DUP repeatedly accused the SDLP of hypocrisy by pointing out that the party's three MPs have yet to give up their Stormont roles.
But the bill survived with one amendment which will delay the ban on a politician serving as a councillor for 60 days after they become an MLA.