Nick Clegg is playing with fire. As someone attracted to pyromania myself I am attracted and admiring. I just want to spell out the danger in terms of democracy and power in response to his article in today’s Guardian.

Nick defends his leading the Lib Dems into coalition in terms of the balance of parliamentary forces and economic concerns. He doesn’t mention Gordon Brown’s bad faith and selfish, closed mentality. Nor the main force behind the Coalition, it orchestrator and conductor, David Cameron, whose audacious project to turn the Tory party back to its one-nation Whig tradition I have analysed in The End of Thatcherism.

But Nick too has a mission: to reform British politics. He has bet his delivery of this on the Coalition. There are two parts to it: liberty and democracy. That is to say, our freedom as individuals and our power as citizens.

Here is what Nick has to say – I’m changing the order – about them:

the relentless incursions of the state into the lives of individuals that has characterised the last 13 years ends here. From rolling back excessive surveillance, to ending the criminalisation of innocent people, we will restore and protect our hard-won civil liberties.

This is tremendous. A transformation of the state is being stopped in its tracks. Of course the drive to build the database state will continue especially from the EU (originally encouraged by the Brown government). Eternal vigilance is needed. But this is an enormous success. Any criticism of the Coalition’s prospectus for democracy must start with a warm congratulation for its promise (and I presume delivery) to protect of our liberty.

When it comes to democracy, however, Nick's precision turns wooly. He says in his final sentence that his party and the Conservatives will, “pursue one simple, shared aim: this will be the government that re-empowers the British people”.

At least he hasn’t promised to enable us. But what does it mean? How empowered will we be? He says,

We will oversee the radical dispersal of power away from Westminster and Whitehall to councils, communities and homes across the nation. So that, wherever possible, people make the call over the decisions that affect their lives.

I am reminded of David Miliband’s equally radical promise of “double devolution”. As Enoch Powell famously said, in Britain “power devolved is power retained”. What he meant was that when sovereignty remains at the centre whatever is “devolved”, “dispersed” or “spread” can always be gathered back like so much confetti. What on earth “double devolution” was supposed to mean was anyone’s guess. But that was the point: it sounded radical. Just as anyone can guess what Nick is talking about when he promises to radically disperse power to communities.

When it comes to councils, they need the power to raise and spend revenues, postcode democracy as Simon Jenkins has argued. This is the test. There has to be a hard edge of the kind that has made a reality of the redistribution of power to Scotland and Wales a success.

Take Nick’s simple pledge that, “wherever possible” the new government will ensure, “people make the call over the decisions that affect their lives”. Well, voting affects our lives. Can we decide our system of voting? Perhaps we would want it to be proportional, perhaps not. If Nick's words mean anything they must mean this, it's undeniable.

When it comes to Tory rule it is traditional to disperse smaller decisions downwards, praising communities and encouraging people to be responsible, while keeping a grip on high politics. Reform of this kind is designed to update central power so as to deprive another generation of constitutional democracy. Don’t do it, Nick.

I am not saying that Labour, who destroyed opportunity after opportunity to democratise Westminster, offered anything better. On this front it was Tweedledum and Tweedlee. What I am saying is that this is at the heart of Liberal Democracy and, Nick, you can’t afford to betray it. You say,

there has already been significant compromise from both sides and there will of course need to be more.

Of course there will. But in this case the compromise must come from the Conservatives to you. If your government is pledged to give the people the right to a referendum on our choice of voting system, you must give us a real choice, not refuse to permit us to consider the options. What was it you say? That we must be “empowered” to decide? That we must “make the call”?

Perhaps you can take David aside and say, “Look, it was your manifesto not mine that was a public invitation to people to join the government of Britain. Now they want to come in and decide on the voting system. Even those who don’t want proportional representation want to be able to have the choice to say they don’t. How can we restore trust if we slam the door on them now?”