One overlooked reason why the Lib Dems are so desperate to secure House of Lords reform is that it would revive the debate around electoral reform. The likely use of proportional representation (PR) to elect the second chamber (as proposed by the government) would allow Nick Clegg to portray the Commons as a less legitimate body and argue for reform to bring it into line with the Lords.
The party president Tim Farron has already argued that "Members elected in a different Chamber by the single transferable vote will have greater legitimacy than those elected to the Commons on a system of first-past-the-post" (see p. 14 of the joint committee report on Lords reform).
As Lib Dem blogger Mark Thompson recently pointed out, it is important to remember that the public did not reject proportional representation last year. They rejected the Alternative Vote, a system that, in some circumstances, can prove even less proportional than first-past-the-post.
Indeed, the No2AV campaign observed:
There are strong principled arguments for and against PR, and it's a debate worth having. The Alternative Vote, however, is a step backward rather than a step forward. AV combines the weaknesses of both systems; it isn't proportional – three out of the last four elections would have been more disproportional under AV
Whether or not the inclusion of a proportional option on the ballot paper would have changed the outcome, it is undeniable that the public have not been consulted on this point.