Who says who stays, who goes?

I'm intrigued by the Constitutional Arrangements established by the Cabinet Office for this election.

As I understand it, if the governing party receives the most seats but fails to gain a majority, it assumes a right to continue in power until winning or losing the vote on the Queen's speech.

Perhaps this is just a formal iteration of an acknowledged procedure. Yet my memory tells me the convention was that the Monarch herself decides who will be allowed to try to form a government.

I'm not actually advocating the Conservatives form an alliance with the LibDems, or with any other parties, but, in theory, there are potentially stronger options available than Brown trying to cling to office with a minority government.

Is this another instance of our constitution being 'modernised' by politicised officials—just like those in Brussels?

I presume the Queen's opinion on this constitutional matter also hasn't been sought.

UPDATE: Wed 5th May
Professor Robert Hazell, of the Constitution Unit at UCL, tonight confirmed the impact of the constitutional arrangements he has recommended for the event of a hung parliament.

If Cameron gains the most seats, but less than a majority, by Friday morning he'll be claiming victory and a right to form the next government—with or without others' help. But according to the newly defined procedures, Gordon Brown will still get first bite at the cherry.

If Brown can fix an arrangement with other parties that could survive the Queen's speech, then he'll be able to continue in government and the Conservatives (despite winning most seats) won't get a chance to offer a plausible alternative.

This doesn't sound very fair to me.

Professor Hazell may be called to defend his recommendation, together with Gus O'Donnell at the Cabinet Office.

N.B. Hazell is an expert in constitutional reform research that is substantially funded by the Economic and Social Research Council (ESRC), which in turn is funded by the Department for Business, Innovation and Skills, which is of course Lord Mandelson's department.