What does the mace represent in the House of Commons?

The mace represents the Queen's authority for the House of Commons to assemble and carry out its functions.

Whenever the House is assembled, the mace must be on the table before the Speaker. When the House resolves itself into a Committee of the Whole, the mace is lowered (to show that the House is no longer performing the functions of the House of Commons by the Queen's authority, but rather as a committee of the more powerful body).

In Canada, a member of the House of Commons once attempted to grab the mace from the table; proceedings were disrupted, and the member (The Honourable Keith Martin) was not allowed to retake his seat until he apologised to the chamber for having challenged the authority of the House.