The cry of 'betrayal' is one of the most oft-heard in politics. Labour faced it on numerous issues between 1997 and 2010, not least when it introduced university tuition fees despite a manifesto pledge not to do so.
"We have no plans to introduce university top-up fees, and have legislated to prevent them" actually translated as "We have no plans to introduce them during the 2001-2005 Parliament, but we will legislate to bring them in thereafter."
The subsequent backbench revolt came close to bringing down Tony Blair, whose government only survived when a few MPs switched sides at the last moment on the orders of Gordon Brown.
One potential North-East rebel was told to support the measure with the words: "I'm not asking you, I'm [expletive deleted] telling you" - an interesting illustration of the way the Brownites used to do business.
But Labour's shameless U-turn created a huge political opportunity for the Liberal Democrats, which they subsequently sought to exploit to the full in constituencies with large student populations.
Among the seats they targeted in 2005 was Newcastle Central, and it was probably only the personal popularity of the then MP, Jim Cousins, that stopped them winning it.
The Lib Dems were again making the most of the issue during this year's campaign, which they fought on a pledge to abolish the fees in place of a 'graduate tax.'
As one Sheffield student told the BBC's Question Time on Thursday: "Nick Clegg was never out of our student union during the election. Now we can't even get a meeting with him."
The reason for that, of course, is that the Lib Dems are now part of a Tory-led coalition that is set to remove the current £3,000 cap and raise it to a maximum of £9,000.
They point out that the coalition agreement does not commit them to supporting the measure, allowing them to abstain when the proposal comes before the Commons.
But if party leader Mr Clegg saw this is some great concession wrung from his Tory partners at the height of those tense negotiations following the election in May, I suspect he has since been disabused.
In fact the public sees it for what it is – a fig-leaf to enable the Lib Dems to stand aside holding their noses while the Tories introduce a two-tier system of higher education.
The purpose of this column is not to go into the rights and wrongs of how universities should be funded and how that fits into the larger question of how to tackle the deficit.
My own personal views on the matter are inevitably coloured by my own experiences as a student in more benign economic times.
As someone who would certainly not have been able to go to university without the state support that was then on offer, I find it very hard to argue that the next generation should be denied the same benefits.
That said, alongside a 'free' university education, in those days you also used to be able to buy houses in the West End of Newcastle for a few hundred quid. It's a different world now.
No, the main point I am trying to make here is that this is yet one more example of the coalition's inherent instability.
It seems likely that a number of MPs, possibly including the former leaders Sir Menzies Campbell and Charles Kennedy, will rebel rather than abstain on the measure, calling into question Mr Clegg's control over his own party.
As the Lib Dem leader has frequently reminded us, compromise is a necessary part of politics, especially in a hung Parliament scenario, and some political promises are seemingly made to be broken
With hindsight, however, I suspect he will come to see this as one that really should have been kept.