Is an elected House of Lords the slippery slope towards federalism?

"Could a future Prime Minister sit in an elected House of Lords?", asked Norman Lamont on Monday.

The answer that came back was "No".

Concern was expressed that proportional representation could confer upon the Lords greater democractic legitimacy than the Commons, and under those circumstances the presence of the prime minister in the House of Commons was required to underpin its primacy. What wasn't brought up by commentators (ConHome, Witterings from Witney and ePolitix to name a few) was the tantalising prospect that the House of Lords might also be regarded as more British, a prospect that was raised by Paddy Tipping a few years back:

Let us consider what would happen if there were two classes of Members of Parliament, and certain MPs could not vote and, in particular, speak on certain issues. If there were a rival Chamber up the Corridor, where Members from across the United Kingdom, however they were elected or selected, were able to speak, there would be a case for people to say, "We are the legitimate Chamber of the United Kingdom, and you Commoners down there are a de facto Parliament for England." That is the threat. I do not say that that situation will arise, but we need to explore the issue.

No one ever mentions the Upper West Lothian Question, except me.