So, Vince Cable has ruffled a few feathers by claiming that the Lib Dems have not gone back on a promise on fees. Given that every simple MP signed a specific pledge to vote agaist a rise in fees, this seems a little odd.

His argument, put simply, is that the Lib Dems didn’t win the election. They are the smaller party in a coalition government. They won’t get everything.

In normal human interactions, signing a piece of paper promising to do something and then doing the opposite is seen as going back on a promise. But I think there is some subtlety to this.

It is true that a coalition government requires each party to vote in favour of policies they don’t support – if they don’t, the government will fall. It is also true that those of us who back proportional representation favour systems more likely to lead to coalition governments. And those Lib Dem activists who remain love to smugly point this out.

But I think it misses the point of a coaliton – it conflaits compromise with complete U-turn.A manifesto is not just a list of policies. It is a vision for the future of the country. There is a fundemental difference between compromising on the route when discussing how to get somewhere, and going in the opposite directon to a completely different place from the one you promised. The Lib Dems secured votes by looking to be to the left of Labour, but now support a political and economic program more right wing than even the Tories proposed during the election. They are not negotiating on the detail, and so throwing a few policy pledges overboard. They have secured votes promising to go one way, then sailed in the opposite direction.

Before the 2007 election, Scottish Greens had a good chat about what we would do if we held the balance of power (as our MSPs now do). We concluded that, during the election, we would make it clear that some of our pledges (no new nuclear power stations) were ‘red line’ issues. We would not support a government if it was going to do these things/refused to do these things. Others were ‘green line’ – these were policies we wanted,/things we opposed, and would try to secure/stop in negotiations. If we didn’t get enough ‘green line’ issues, we wouldn’t do a deal, but we didn’t promise that we would never support a government without all of them. Voters, and journalists were clever enough to understand this (usually). And when, after the election, our MSPs went into negotiations, they felt that they didn’t secure enough to do a long term formal deal. So they made specific short term arrangements, and backed out, promising co-operation on a case by case basis.

Given the speculation around a hung Parliament before the election, you would have thought the Lib Dems might have considered what they might do if it happened. And going into the election with a clear mandate for particular policies might have been a good way to manage that relationship.

But the truth is that you don’t need to explicitly say what your red lines are, and what your green lines are. Because voters know. Red lines are the things you campaign on – the stuff that you put front and centre. Green lines – the things you might drop in coalition negotiations – are the things in your manifesto, or buried in the longer leaflets, that don’t persuade hundereds of thousands to go out and vote for you.

And it’s pretty clear that tuition fees was a red line issue for the Lib Dems. I haven’t heard anyone grumbling aout the Lib Dems not securing their preferred model for local taxation. People understand that some things will be lost in the mix. But if every MP has signed a pledge, then the issue is a red line.

Vince’s argument might even be reasonable (from a democratic perspective) if the proposal was to maintain fees as they are, rather than scapping them (which is what they proposed). But to get elected promising to scrap tuition fees, and then, a few months later, to trebble them – is clearly a ludicrous abuse of the trust placed by voters.

So, yes, democracy is a clumsy negotiation towards a compromise. Yes, I support systems which are likely to deliver coalitions. And yes, sometimes that means parties won’t deliver policies they want to. But that doesn’t give carte blanche to ignore what you promised. Lib Dem candidates made it clear that fee hikes would be a red line issue for them. They secured tens of thousands of votes for doing so. The need for compromise to secure short term stability is irrelevant compared to the risk of a generation being taught the dangerous false lesson that voting changes nothing. And the need of Lib Dem ministers to keep their jobs is nothing to the hopes they will destroy if they allow these fee hikes to go ahead.