The Big Question: After 10 years, how close is Labour to reforming the House of Lords?

Why are we asking this question now?

Reform of the House of Lords has been a recurring theme of the Labour government since it swept to power in 1997. Tomorrow sees the latest attempt to break the political logjam and secure a lasting solution to one of the longest-running constitutional arguments in British politics.

Jack Straw, the Leader of the House of Commons, is expected to publish a White Paper outlining far-reaching proposals for a part-appointed, part-elected upper house which, he hopes, will be the cornerstone of the British constitution for the 21st century. MPs will hold a free vote on the issue next month.

Does the Lords need to change?

To its critics, today's House of Lords, filled with appointed life peers, a rump of the old hereditary members, a smattering of bishops and senior judges in the shape of the serving law lords, represents an unelected bloc that is fundamentally at odds with the principles of democracy. To its defenders, the appointed upper chamber allows expert peers, untroubled by the short-term requirements of elections to scrutinise and, if necessary, delay laws in the long term interests of the public.

Ironically, even opponents of an unelected body at the heart of government have praised the actions of the upper house. The Lords has acted as a bulwark against the Government, challenging ministers - and securing important concessions - on a string of civil liberties issues, including anti-terror legislation, ID cards and trial by jury.

Concerns have been expressed that reforms - particularly any move to require all peers to be elected - could remove eminent former lawyers, civil servants and other public figures who add to the detail and thoughtfulness of debates. "We don't just want people who want a stepping stone to the Commons," said one peer.

Constitutional reform has also been given new impetus by the cash-for-honours investigation, which has thrown a spotlight on how, and why, people find themselves nominated for a peerage.

Who sits in the Lords at present?

There are 732 members of the House of Lords. The vast majority, 615 peers in all, are life peers appointed by political parties. A handful are so-called "people's peers", chosen by the Independent Lords Appointments Commission.

The total also includes 91 former hereditary peers, who were allowed to remain in the upper house under a deal brokered when Labour removed the vast majority of hereditaries in 1999. One seat for a hereditary peer is waiting to be filled; under one of the odder by-products of the reforms, hereditary peers can vote in a by-election for one of their number to take up a seat.

There are also 26 bishops and archbishops of the Church of England and 26 law lords.

Why is Labour taking so long to reform the upper house?

Lords reform under Labour has a long history. A very basic chronology of the issue since 1999, produced by the House of Lords Library, runs to 44 pages. Tony Blair's government took the first step to reform the House of Lords in 1999, removing hundreds of hereditary peers. However, in what was very much an interim deal between Mr Blair and the then Shadow Leader of the Lords, Viscount Cranbourne, 92 hereditaries remained. Since then, attempts to secure consensus in Parliament, or even in the Cabinet, have foundered, despite a Royal Commission, an inquiry by a joint committee of MPs and peers, and two White Papers.

Initial proposals for a largely appointed chamber, produced by the then Lord Chancellor, Lord Irvine, foundered. The late Robin Cook's attempt to find a "centre of gravity" around a largely elected House of Lords collapsed in chaos when MPs failed to secure a majority for any single option. The conflicts inside the Cabinet were also laid bare when Mr Blair made plain his support for a wholly appointed chamber to avoid a hybrid Lords or a full-blown rival to the Commons.

Ministers have also grappled with the historic powers of the House of Lords, which can delay legislation for up to a year, a power that allows peers to cause ministers enormous problems.

What proposals are on the table?

Jack Straw is expected to propose a hybrid house, with half the members elected and half appointed. The White Paper is thought to suggest giving party leaders the right to recommend 30 per cent of the members in a reformed second chamber, with the remaining appointed members chosen by an independent commission. The other members would stand for election at the same time as the European Parliament, with candidates chosen from party lists.

Under the proposals, MPs will be given a free vote on the make-up of the Lords. They will choose from a string of options: all peers elected; 80 per cent elected, 20 per cent appointed; 60 per cent elected, 40 per cent appointed; half and half; 40 per cent elected, 60 per cent appointed and; 20 per cent elected, 80 per cent appointed. To avoid the fiasco of the last Commons vote, MPs would be given a "preference vote" under which they would list options in order of preference: votes for the least popular options would be redistributed until one option secures a majority.

The Lords would be cut from 748 members to about 540, with elected peers serving fixed terms of about 15 years. A voluntary severance package would serve to encourage current peers to give up their seats. There would also be increased safeguards on membership to prevent allegations of sleaze. The Government seems to have backed away from curbing the powers of the Lords to delay legislation or imposing timetables on their - entirely self-regulated - debates.

How will the parties react?

The Cabinet remains split on Lords reform, although there is probably a majority on the Labour benches for a mainly elected house. In 2003, reformers came within a handful of votes of securing backing for an 80 per cent elected chamber. All parties now broadly back a significant elected element to the House of Lords. However, there are concerns about the detail.

Liberal Democrats fear a half-and-half split between elected and appointed peers would leave room for political appointees to dominate. They also worry that basing elections on party lists will divorce even elected peers from the voters. The Tories say they have been trying to achieve consensus around a "substantially elected" upper house, but have argued that elected peers should face first-past-the-post elections in constituencies based on counties and major cities. Peers would also have to back the package, and whether they will agree remains an open question.

Will Labour's latest attempt to reform the Lords succeed?

Yes...

* The cash-for-peerages investigation and Labour's desire to complete its reforms have created a momentum for change

* There is now greater consensus on the merits of a part-elected, part-appointed House of Lords

* MPs will vote on the plans next month, and a way has been found to prevent the chaos of the last Commons vote on Lords reform

No...

* It is unclear whether peers will agree to hundreds of their number losing their seats

* There are still disagreements running through the parties, from the Cabinet downwards, about how best to reform the Lords

* Despite its anachronistic structure, the Lords does a reasonable job in holding governments to account and fixing badly drafted laws