In our February White Paper we proposed a `hybrid' House, believing that this safeguards the primacy of the Commons and allows for a second chamber which can call on the expertise and experience of non party-political members, while introducing a direct relationship between the Lords and the electorate. This has also been the view of several influential studies, notably the Royal Commission of 2000, the Public Administration Select Committee report of 2002 and the all-party Breaking the Deadlock group in 2005.

I have changed my own view since the last free votes in 2003. I have come to the conclusion that it is difficult to justify a second chamber where the public has no direct input into who sits in that chamber.

Among those who support this argument, there are a range of views about the proportion of the House which should be elected. Some favour 80%, others 60%. The Breaking the Deadlock group suggested 70%. I have proposed a 50% elected second chamber.

My appeal to all those who support election as part of Lords reform is this: don't make the best the enemy of the good. If our votes splinter and are spread across the `hybrid' options, all might fall: if we set aside our view of perfection and instead vote for progress, we have a better chance of success.

That is why I will be voting for elected elements of 50%, 60% and 80% next week. If we secure a vote favouring an elected element in the Lords, we will have taken a momentous step forward, whatever the proportion which receives most support. If all options are defeated as in 2003, discussions about the size of any elected element in the second chamber will be merely academic.  The free votes therefore represent a crucial step towards breaking the deadlock on this issue.

I appreciate that this argument is irrelevant to those who are opposed to election of any kind to the second chamber. I respect their view that the introduction of elections could threaten Commons primacy. I have no interest in doing anything which threatens this fundamental concept or which creates a rival to the Commons.  It is not, however, a zero sum game. Introducing elections to the Lords will not lead inevitably to a reduction in Commons power: indeed, the role of the Commons as the primary chamber is underpinned by the Parliament Acts. The evidence of second chambers overseas is that election does not necessarily lead to increased power: some all-appointed second chambers are much more powerful than others which include an elected element.

There is now a wide consensus that the status quo on the Lords is unsustainable, and that the way forward is with a `hybrid' House. Radical constitutional reform has been one of the defining characteristics of Labour in power since 1997. But this time we need a clear decision on Lords reform; not a repeat of the 2003 impasse.

Here is the recent Labourhome interview with Jack Straw.