Wiktionary
n. (context politics English) A majority big enough for the party or faction in power to carry through most of its legislative programme without the risk of parliamentary defeat.
Wikipedia
Working majority describes a parliamentary majority big enough for the party or faction in power to carry through most of its legislative programme without the risk of parliamentary defeat.
Usage examples of "working majority".
That had seemed reasonable, with Tonkovic's party and its allies' control of the presidency and a working majority in Parliament.
Benjamin IX and his Council, as well as a working majority of the Grayson Keys, recognized the unique and dangerous balance of political power within the Star Kingdom.
The Government possessed a working majority, but that was the result of the support of two dozen of the nonaligned peers.
At the moment, the Opposition parties have united in a solid front against the Centrists and Crown Loyalists, which leaves Duke Cromarty short of a working majority in the upper chamber.
I understand that Elder Torine has only a thin working majority, and that you Normists wish to retain power.
Could any one sect obtain a working majority at the polls and take over the country?