quorum

Definition
The minimum number of members required in a house of legislature before business can be done. In Australia it is 25% of Senators and 20% of MHRs, while in the USA in both houses it is simply a majority, although in the Senate it can be less if there is no objection by any member. In the UK it is 6.2% for the House of Commons, although no minimum for business not involving a division (vote).