Should Lords be allowed to speak in the Commons?

"It emerged today (at morning lobby) that Gordon Brown has exchanged letters with the Speaker over the idea of letting ministers from the Lords answer questions in the House of Commons.

The case in favour is that this will make peers such as Lord Myners or Lord Davies more answerable to the public.

The case against - put by Ken Clarke yesterday - is that it could erode the legitimacy of the House of Commons. Over a decade or two, he argued, prime ministers could pick ever more of their cabinet from outside the chamber; and that would be bad for democracy."

I think they need to find a way to face each other. If Lords csn't speak in the commons, maybe MPs in the Lords. Or somewhere else.
I'm not too keen on Lords being ministers for this reason, it needs sorting