Despite the rifts, the Coalition will stagger on until the election. But can you imagine Cameron and Clegg reunited in the rose garden?

There are Tory MPs aching for a brief period of minority government

The two parties in the Coalition row noisily. The noise is more significant than the substance of the arguments. The latest eruption is between Michael Gove and senior Liberal Democrats, but listen to Tory MPs, and the Education Secretary is by no means alone in his disdain for… who/what?

Belatedly the Liberal Democrats fight back. They have no choice, as they struggle to avoid a catastrophic outcome in this month’s elections. With Ukip breathing down their necks, the Conservatives are likewise compelled to stress how different they are from their partners in government. From free schools to crime and, of course, Europe, the electoral pressures oblige the two governing parties to show how much they disagree with each other.

In recent days I have spoken to senior figures from all three main parties, and they all contemplate the possibility of a break-up of the Coalition before the election next year. A member of the Shadow Cabinet suggests that the TV debates will be the trigger.

David Cameron has made clear that he wants some or all of the televised events to take place before the campaign gets under way, rightly arguing that the last ones sucked the life out of the contest, as well as his hope of securing an overall majority. If the debates are staged earlier, some in Labour predict that the Coalition will end this autumn, on the basis that it would be unsustainable for Cameron and Clegg to debate on TV as PM and Deputy PM.

Meanwhile, some Liberal Democrats assume that a slaughter in this month’s elections will lead to fresh calls for an end to the Coalition so that their party can assert its distinctiveness decisively. On the other side there are Tory MPs aching for a brief period of minority government.

In spite of these hopes and arguments, an early ending will not happen. Party self-interest is too complex. Above all other considerations Nick Clegg needs to argue at the election that coalition government works in the UK. If this one breaks up prematurely in a mood of mutual animosity, his already limited arsenal of arguments in favour of coalition disappears completely. The claim “Coalition works”, as he strides out early from the current one, will strike yet another discordant note, as difficult to explain as his opposition to tuition fees at the last election.

For Cameron to lead a minority government for a few months would be a nightmare, at a time when he needs to appear at his most authoritative. Both sides will cling on until the end. They have agreed a Queen’s Speech over which they can unite on the few occasions when Parliament sits between now and the election.

But the public tensions will have one very important long-term consequence. They make it impossible for another Con/Lib Dem coalition to form after the next election. Governing is partly dependent on a sense of unity and purpose. The early energetic phase of the Coalition, although leading to some ill thought-through policy-making, had both. All governments suffer from fuming divisions, but this one is unique in that it is now in the interests of the governing parties to highlight the tensions rather than suppress them. Acts of public hostility sap a political project of life in a way that private divisions do not.

Gove, an early enthusiast for the Coalition and one of those who wondered whether the partnership would lead to a permanent realignment on the right, clashes with senior Lib Dems over so-called free schools. He is one of the heroes of the right-wing media, and in much of his party, for the depth of his ideological convictions. It is impossible to imagine another five years of Gove constrained by Lib Dems, even if his convictions are transferred to another department. The same applies to a range of Tory ministers on the radical right.

On the other side Clegg told Paddy Ashdown in 2010 that he thought the Tory party had changed under Cameron’s leadership. Ashdown explained to me recently in a BBC interview that they both realise Clegg’s verdict on the Tories then was too generous, while still passionately defending the decision to join the Coalition. Again the public nature of Ashdown’s observation is significant.

A second Con/Lib coalition would seem like an act of dishonesty rather than a sincere attempt to respond to the voters’ indecision. What would Cameron and Clegg say when they held a joint press conference a few days after the next election? How could they declare their readiness to work together for another five years when their parties had disagreed so loudly for the previous 12 months?

One consequence of fixed-term parliaments is that at the beginning the course looks intimidatingly long, like the start of a marathon. These two parties will run raggedly together towards the finishing line. They will be in no state to start a second marathon after the election.

Twitter: @steverichards14