Ratty, you display your ignorance. Constitutionally the convention is clear. The sitting PM has the first go. If he fails then the wily old constitutional lawyer on the gold chair, her maj (who has consistently shown better political nous than the parties, apart from her perfectly correct views about the church of Diana the Martyr in which she failed to grasp the stupid sentimentality about the "people's princess") should send for the person she judges most likely to be able to form a government - but for over 50 years (I'd have to look up the date) that crown prerogative has been exercised only on advice and not as a matter of political judgment.

IMHO Clegg has now shown himself to be slimy and unprincipled public schoolboy (from Westminster) and if he buys into being "Dave"'s bumboy he will destroy the LibDems. He may have done it already.