Peers are voting on who should be the first House of Lords speaker.
The Lords Speaker will not be a member of Cabinet
It marks the beginning of the end for the post of lord chancellor as presiding officer of the upper house.
Three women and six men are competing for the lucrative £101,000-a-year role, which comes with an apartment and a £10,000 gold and silk robe.
The new speaker, who will be named on 4 July, will be elected for a five-year stint, be independent of government and will act as a Lords' ambassador.
The office of lord chancellor dates back to the Norman Conquest.
An attempt to axe the title has been dropped but instead it has been modified.
The lord chancellor is no longer head of the judiciary and is now set to give up his role as speaker of the House of Lords.
But Lord Falconer keeps the title of lord chancellor. He is also constitutional affairs secretary in the Cabinet.
As well as the salary and expenses, the new speaker will also have use of part of the lord chancellor's apartment in the Lords in return for sitting on the woolsack (which is where the lord chancellor currently sits) for about three hours a day.
Lords' officials say the apartment will be used for receiving foreign dignitaries and although it includes overnight accommodation, it will not be a grace-and-favour residence.
The new speaker will not have to wear a wig - they will just wear a gown in the chamber.
Runners and riders
Their authority will be limited. He or she will be able to help peers out on points of procedure, have a say whether or not to allow short debates on urgent issues but they will not have any of the powers the Commons' speaker has to intervene.
Former Commons Speaker Baroness Boothroyd said the Lords wanted its own speaker.
"It's needed to get away from the lord chancellor - somebody who is a political animal, appointed by the prime minister, who is a member of the Cabinet..."
Lady Boothroyd said she would have liked the Lords speaker to have more authority so they were able to bring peers to order "in a gentle way" if they moved away from the main issue of a debate.
Candidates competing for the job are:
- Lord Boston of Faversham, a crossbencher and former MP and minister
- Lord Elton, a former Conservative government minister
- Baroness Fookes, Conservative peer and former Commons deputy speaker
- Lord Grenfell, the chairman of the Lords European Union Committee
- Baroness Hayman, former Labour MP and minister
- Countess of Mar, independent peer who has been a deputy chairman of committees since 1997
- Lord Redesdale, Liberal Democrat frontbench spokesman and scion of the Mitford family
- Lord Richard, former Labour Leader of the Lords
- Viscount Ullswater, a Conservative peer and a current deputy chairman of committees.
Work and Pensions Minister Lord Hunt has said he doubts the job would be limited to about 12 hours a week as there was "a lot of other work to do, committee meetings and a general leadership role".
He also defended the need for a £10,000 gown as "reasonable" and "an indication of their role and status".