Much the same might be said of Tim Montgomerie's advocacy of a "manifesto mandate" for a "fundamental renegotiation" of British membership, in his interesting, provocative and obviously well informed post about the Tory search for a European policy.
The only thing that may not be clear is whose Trojan Horses they might be.
The first thing to note is that it gets David Cameron off-the-hook of his "cast iron pledge" to hold a referendum. The willingness of Tory insiders to talk on background terms to ConservativeHome about their detailed thinking looks like an important part of the softening-up exercise, so that the official announcement that David Cameron has ditched his "cast iron pledge" is barely newsworthy at all when it arrives. Montgomerie reported in his comments thread that "my post is obviously not an official announcement of Tory policy. It reflects about a dozen conversations with inside-the-machine people yesterday. I'm confident it is pretty accurate in all key respects".
However, there is a deep confusion in Montgomerie's advocacy on the EU issue.
It might be that theory of the "manifesto mandate" argument for a "fundamental renegotiation" may well be designed and intended to use "all necessary guerilla tactics" to place Britain in a condition of permanently aggravated tension, so that an amicable divorce is increasingly seen as a more sensible option in the EU itself as well as in Britain. (Montgomerie wrote in Fabian Review this Autumn that "I support leaving the EU. I'm a critic of the EU primarily because it has diluted democracy. Voters should be able to change the way they are governed and they can't change the supranational regime in Brussels").
However, the "manifesto mandate" theory could, in fact, turn out to be a poison pill for Euroscepticism after all.
One needs to separate the theory of democracy being advanced from the content. The democratic theory which grounds a "manifesto mandate" argument is surely this: 'our representative Parliamentary democracy can decide on EU policy' and that 'the British people are asked about the European Union when there is a General Election'.
So it is that Montgomerie offers his fellow Eurosceptics a strategy which would fatally undermine a key Eurosceptic talking point: that no voter under fifty has had a say on British membership of the European Union, and that its development lacks democratic legitimacy.
The theory of a "manifesto mandate" has already sold out a core premise on which the argument for a "fundamental renegotation" rests.
Montgomerie's position is that a referendum is unnecessary: he insists that a "manifesto mandate" will suffice. He goes on to call for it to be a mandate calling for a fundamental renegotiation. But if the theory is that democratic legitimacy will come not from a referendum but from the content of the manifesto, how can that theory be that this depends on it being a manifesto mandate which Montgomerie agrees with?
It sounds like Montgomerie's own preferred EU policy could be captured by putting something rather unlikely in the manifesto such as "John Redwood will lead a Conservative government's fundamental renegotiation of the terms and conditions of Britain's membership of the European Union, leading to some different membership status for Britain to the rest of the European Union".
Can Montgomerie explain why the content of his proposed manifesto pledge would offer a future
Conservative government a mandate from the British people for their EU policy, while a manifesto mandate to which said "we do not support further EU integration, but will not seek to reverse what has already been ratified by Britain and her European partners" would not do so?
That would surely be a "manifesto mandate" to live with Lisbon, and get on with focusing on schools policy and the public finances.
Or even "we will place Britain at the heart of EU decision-making and work within the new Treaty arrangements to pursue British interests and international goals", were any party so bold as to propose that.
Clearly, there are challenges to the working of representative democracy in respect of a 'mandate' theory, since nobody can claim that every voter endorses every policy of their chosen party or candidate. But that is part and parcel of representative democracy.
The specific Eurosceptic objection has been that a political consensus on the European Union has meant that there has been no choice in General Elections, and that this matters because the issue is of fundamental importance to our democracy. That explains the apparent paradox as to why the most fervent defenders of Parliamentary sovereignty have been decreasingly willing to let Parliament decide these questions.
But how far is this the case?
Firstly, those advocating this new theory would surely accept that "manifesto mandates" got Britain into the European Economic Community in the first place. There were significant disagreements between the manifestoes of the major parties on European policy between 1959 and 1974, and Ted Heath explicitly sought a "manifesto mandate" to negotiate entry in the Tory manifesto in 1970:
If we can negotiate the right terms, we believe that it would be in the long-term interest of the British people for Britain to join the European Economic Community, and that it would make a major contribution to both the prosperity and the security of our country
Only when we negotiate will it be possible to determine whether the balance is a fair one, and in the interests of Britain. Our sole commitment is to negotiate; no more, no less. As the negotiations proceed we will report regularly through Parliament to the country.
So Montgomerie could propose that David Cameron make clear that his European policy is to follow the 'Ted Heath model' and make exactly this type of pledge, if to opposing ends. The argument is for a "trust Dave" call to give him a free hand, and to argue over how he should play it.
This will hardly, however, convince Eurosceptics who share Daniel Hannan's view that every Eurosceptic politician turns soft in office, with heroes from Margaret Thatcher to Vaclav Klaus not exonerated.
Labour's argument for a referendum on the EEC was one of the major themes of the 1974 election campaigns, leading to Enoch Powell's advocacy of a Labour vote. (And the common claim that the 1975 referendum was only debating a "free trade area" is undermined by analysis of the advocacy of both the yes and no campaigns in 1975, in which arguments about sovereignty were very prominent).
It is true that the major parties became less likely to advocate withdrawal after the referendum to stay in, largely because most people felt this had settled the question until the 1990s at least. But the major parties have run on EU withdrawalist manifestos - as Labour did in 1983 - and highly Eurosceptic manifestoes, as the Tories did in 1997, 2001 and 2005. On each of those occasions, there was a significant difference between the manifesto commitment to EU engagement of the Thatcher governments in 1983 (and 1987) and the Labour party in 1997, 2001 and 2005. This Eurosceptic argument of 'never being asked' also depends on the objection that the opportunity to vote for high profile parties with an EU withdrawalist ticket - such as the Referendum Party in 1997, or UKIP at the next election - does not count, unless one of the major parties offers a withdrawalist platform too.
However, the argument that "the British people have not been asked for thirty-five years" is a plausible rhetorical argument which can be made by those arguing for another referendum on British membership. (And I would support the idea that an "in or out" referendum is again necessary to settle the question of UK membership for another generation).
But this can not be advanced by those seeking a "manifesto mandate" instead of a referendum, because successive British governments have had manifesto mandates for their European policies.
Finally, a specific argument is made about the last election. Both parties promised a referendum on the EU Constitution.
Labour ditched that commitment, on the grounds that the circumstances had changed. (The argument was that the Constitution was dropped, and replaced by the Lisbon Treaty is no longer the Constitution: the Conservatives have argued that those are weasel words to escape the pledge).
Hence David Cameron offering the "cast-iron guarantee" of a referendum on "any Treaty" which arose from the negotiations. That Conservative commitment is now being ditched, on the grounds that the circumstances have changed. (The argument that this only applied to an unratified Treaty is being attacked by Eurosceptics inside and outside of the Tory party as weasal words to escape the pledge).
Perhaps this argument can be advanced. There may, however, be some problems with it being advanced by the Conservatives.