Steve Richards: Novelty won't sustain this alliance

David Cameron has always been a brilliant choreographer, and he will manage the Tory right and the Lib Dem left with attentive charm

It took a few days to get there, but the formation of a new government marks an historic break with the past. The pragmatic Conservative leader, David Cameron, has no choice but to become a revolutionary prime minister. His party returns to power in alliance with another. They are not used to this and nor are we.

In the end it was parts of the Labour Party that turned away from the Liberal Democrats and the possibility of a further term. Some Cabinet ministers were unhappy about a deal. A chorus of Labour MPs declared that they were opposed. They head for the deceptive comforts of opposition rather than face the hurdles of a new, precarious coalition.

There were some solid arguments for their stance. The voters would have disapproved, perhaps with a dangerous intensity. Such a coalition might not have lasted for very long. Quite a lot of them were opposed to a change in the voting system and were alarmed at the possibility that concessions were being made in negotiations without wider consultation.

There is much talk among Labour MPs of the need to regroup in opposition. I wonder whether they will feel quite so sanguine if they are out of power for decades. There was a similarly complacent mood among some Labour MPs after their defeat in 1979: let the Conservatives take the unpopular policy decisions and we will be back under a new leader at the next election. They returned to office in 1997.

From Labour's perspective I am told that by yesterday morning the mood of the Liberal Democrats' negotiating team had changed completely from the night before. The Liberal Democrats no longer seemed interested. Some of Labour's negotiators sensed the Lib Dems had been terrified by the onslaught from some of yesterday's newspapers. But in fairness to Nick Clegg it was impossible for him to sign up to an arrangement being condemned by some Labour MPs. For both parties it was a lost opportunity and one that is unlikely to resurface for a long time. In relation to electoral reform the best that the Lib Dems will get now is a referendum on the Alternative Vote, which is not a significant change. For Labour it has opted for opposition when power was still possible.

Labour's leadership contest becomes a pivotal event. A leader is required who can revive a tired, bewildered, divided party very quickly. The opportunity is there. The new government will face nightmarish challenges. The Liberal Democrats will be signed up to those daunting demands too. Labour becomes the only alternative for the time being. But the division that has surfaced in recent days is a fundamental one, defined neatly by those that were excited by the prospect of a progressive alliance with the Lib Dems, and the many who were horrified at what was happening.

The younger generation will have room to breathe after the dominant Blair/Brown duopoly. They need to start breathing with gusto. The new leader must be an effective public performer on TV and at the despatch box in the Commons against the quick-witted Cameron. He or she will need to have ideas that move the party on from the Blair/Brown era and link them to convincing policies. This is not easy, as Cameron demonstrated in opposition when he failed in the difficult task of turning slogans into a coherent policy programme, one reason why he failed to secure an overall majority. Waffle about "empowerment" or "choice" will get a new leader nowhere unless it is backed up by a clear philosophy and concrete proposals that are conveyed accessibly.

Above all, the candidate must have an authentic voice, one that has no echo with recent figures, matched by ruthless self-confidence. Being leader of the opposition is the second most difficult job in British politics and in some ways more demanding than being Prime Minister. Like the Conservatives in 2005, Labour should have a long campaign to fully test the aspirant leaders in every context. Whoever wins must begin the task of giving shape to a party that has ceased to know what it is for.

The stakes are high for Labour because the new government begins its life unavoidably as the most fragile in recent history, as well as the most distinctive. At some point the Conservatives face a referendum on electoral reform that they will oppose, an awkward contortion. Some of them look forward to raging about Europe. Quite a few regard the inevitable spending cuts as a great opportunity to create a much smaller state. They do not seem concerned that if cuts were such an opportunity the Thatcher governments failed to make them in the 1980s. In that troubled decade the rate of growth in spending was cut. There were no real terms reductions.

For the Liberal Democrats there are opportunities and enormous risks. Finally they are in power. After all the decades of impotent opposition and eternal talk about realignment on the centre-left, some of their MPs will be in the Cabinet working with the Conservative Party. They have crossed a threshold more quickly than Clegg dared to envisage when he became leader.

But there will be pain to come, in terms of deep unease within the party about their new alliance and also about the longer-term political implications. If the government is perceived to be a success, the Conservatives will almost certainly get the credit, or will make sure they do. If it is a failure, both parties will suffer. I do not anticipate an outbreak of Clegg-mania at the next election.

But at first, novelty will keep the show on the road. The new-look arrangement will get a soaring honeymoon in the polls. The Conservative-supporting newspapers will scream with joy now that Labour is ejected. There will be a lot of naïve support from the gullible wing on the centre-left, who will argue that this is "new politics", as if being "new" is an end in itself and ideological differences are unhealthy.

Cameron will be an astutely skilful manager of his government. He has always been a brilliant choreographer and will manage his right and the Liberal Democrats' left with attentive charm. I suspect also he will get a certain pleasure from the fact that as the "heir to Blair" he leads a government that Tony Blair once envisaged from the perspective of the centre-left but never dared to form. The Conservatives will be disciplined after so long out of power. At first the Lib Dems will be too.

Nonetheless, ideas and values still matter in politics. Novelty cannot sustain a government for ever. There are reasons why people join one party rather than another. New Labour suffered for its extreme pragmatism, trying too hard to please voters and newspaper proprietors with views far removed from its own. Sooner or later such expediency becomes unsustainable. Parties have boundaries. I cannot see how a Eurosceptic party with deeply held convictions about tax, public spending and the role of the state can work for very long with a pro-European party, one that stages an annual party conference that often veers to the left of Labour's.

Cameron leads a revolutionary government but will need his pragmatic skills if it is to rule in this form for very long.

s.richards@independent.co.uk