front bench

from The American Heritage® Dictionary of the English Language, 5th Edition.

• noun The first bench on either side of the aisle in a parliament, reserved for ministers and leaders of the principal political parties.

from Wiktionary, Creative Commons Attribution/Share-Alike License.

• noun UK In the House of Commons, either of two benches nearest the floor of the chamber, one occupied by the members of the Cabinet and the other by the Shadow Cabinet.
• noun Those Members of Parliament occupying the front benches.