Dr Andrew Blick, a Senior Research Fellow at Democratic Audit, and Lord (Peter) Hennessy have co-authored a new report called The Hidden Wiring Emerges. (It provides the best and most comprehensive analysis yet of the Coalition’s draft Cabinet Manual, published in December 2010.

The whole document – and the whole report on it – should attract anyone concerned with the health of our democracy. However, one point of dispute may interest Liberal Democrats in particular.

The authors highlight an idea described in the Manual that, following the resignation of a Prime Minister after a General Election, the person ‘seemingly most likely to be able to command the confidence’ of the House of Commons should be appointed as new Prime Minister.

“Some commentators”, say the authors, “have argued that the actual convention in circumstances of a House of Commons with no overall majority is for the leader of the largest opposition party specifically to be given the first opportunity”.

The authors are concerned that the Manual makes a new rule in this area. But it doesn’t. The Government is simply describing what it believes the convention is, and in doing so it has the support of recent events.

Consider the scenario that would have occurred if the numbers in the Commons had been different after May 2010; perhaps with different arithmetic the Liberal Democrats could genuinely have “chosen” whether to work with Labour under a new Leader (i.e., not the Prime Minister in office at the time) or with the Conservatives, promising to defeat in votes of confidence the party they had not chosen. It seems inconceivable that the Sovereign would appoint as Prime Minister the leader of a party which had not won the election, and could not persuade another party to support him in the Commons. There would be no point, whatever the “commentators” said about it. So the Manual seems to describe plain common sense with some degree of accuracy.

In any case the Manual, for now, should be seen simply as the Government’s view of present practice; certainly Parliament and the Judiciary are not bound by it. Neither is the Sovereign.

What these two academics only scratch the surface of is whether a document of this kind could be used formally to agree some of the relationship between, for example, Parliament and the Executive. In those circumstances it would have more constitutional – if not actual legal – force, becoming a manual not just for this Coalition, but for forming new ones in future.

Watch this space.