Cross-posted from The Wardman Wire:

With reform of the House of Lords back in the news following the latest scandals over who is in it and how they behave, now seems a good time to provide some background on its political make-up.

Since political parties first emerged in British politics, the then wholly hereditary House of Lords consistently had a very large Conservative majority.

For example, in 1900 there were 354 Conservative peers out of the 574 adult peers, giving a “majority” of 134. By 1938 it had grown to 761 adult peers, and of these 519 were Conservative, giving a “majority” of 277.

The introduction of life peerages after the Second World War allowed a wider range of people to be brought in to the Lords, and as a result the political balance also shifted. By 1998, there were 1,272 peers, but of them only a minority now were Conservative – 496.

The Conservatives were still by far the largest political group (158 Labour, 68 Liberal Democrat in 1998 for example), but their lack of an overall majority meant that significant potential power lay with the cross-bench (independent) peers who, if they turned out in large numbers, could decide votes.

Indeed, during Mrs Thatcher’s time as Prime Minister the Lords did cause some significant political headaches, causing the Conservative Lord Bruce-Gardyne to comment that, “No Tory government in modern times has been so consistently savaged by the watchdog once described as Mr Balfour’s poodle.”

This political muscle was primarily driven by the lack of a Conservative majority in the House of Lords, rather than by significant numbers of Conservative peers rebelling against the party line. Though party discipline is often portrayed as being weaker in the Lords than the Commons, during 1988-9, for example, only 40 Conservative peers voted against their party line more than once.

The advent of Tony Blair in 1997 brought about major, albeit only half-completed, changes in how the Lords is composed. Removing most of the hereditary peers in particular fuelled a major change in the political balance.

In 2007 there were 746 peers, down from 1998’s 1,272, but now Labour are the biggest party, albeit with a minority. It is still the case that the need to listen to and persuade people outside your party in order to get legislation through is driven by the lack of a majority for any one party as the overall levels of rebellion against the party line continue to be very low as James Graham has pointed out.

The current composition of the Lords is:

• 614 life peers
• 12 Law Lords (who remain in the Lords when they retire from their legal post, but not under this category)
• 26 Archbishops and Bishops (who do not remain in the Lords when they retire from their church posts)
• 92 Hereditary peers, the remnants from Blair’s half-completed reforms

Of these there are:

• 217 Labour
• 197 Conservative
• 72 Liberal Democrat
• 246 other