The Blair coalition among Labour MPs is fracturing rapidly. That is why tonight’s Commons vote on Trident matters. The result itself is not in doubt. MPs will vote for the status quo: the continuation for another 40 or more years of the 40-year-old bipartisan policy of maintaining a nuclear deterrent. More significant is that a large number of Labour MPs will revert to their preBlair instincts.

For the Government, and the Commons, to have abandoned the deterrent would have been bold, indeed revolutionary. Three months ago Tony Blair posed the alternative of announcing that Britain was “giving up its nuclear deterrent: I just can’t see it”. That is also the view of the Conservatives, who will ensure that the Government has a majority.

In itself, the current decision does not involve any increase in Britain’s nuclear capability. The number of operational warheads will be cut from fewer than 200 to fewer than 160, after big reductions in the British nuclear arsenal since the end of the Cold War. The vote is essentially about developing three or four new submarines to replace the Vanguard class, which will start coming out of service in 2022.

At one level, the argument is about timing, with some Labour MPs and the Liberal Democrat leadership arguing that the decision does not have to be taken now. Ministers insist that it will take 17 years to develop a new system. The Defence Select Committee in its recent report questioned this claim. But arguing for a postponement, as Lord Kinnock has, is a diversion. Even if the programme does not have to be started precisely this spring, the go-ahead will have to be given soon. (One unstated reason is that Mr Blair and Gordon Brown want to resolve the matter before their handover).

Expert View

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A more serious objection is that the end of the Cold War means that Britain no longer faces a threat requiring a nuclear deterrent. On this view, Trident can hardly deter al-Qaeda. Yet there are still states with “dubious intentions” that sponsor terrorist groups and, since the Trident replacement is due to last until 2050, no one can predict what threats might exist then, especially given changes in Russia.

For many Labour and some Lib Dem MPs, however, it is a matter of morality. Possessing nuclear weapons is plain wrong, the old cry of CND and unilateralists, as is vividly brought to life by Kenneth Morgan’s new biography of Michael Foot.

The Government has tried to take the sting out of the revolt with an innocuous motion talking merely of taking “the steps necessary to maintain the UK’s minimum strategic deterrent”. Also, as Philip Cowley and Mark Stuart, of Nottingham University, point out in their prevote note, the result may be muddied by abstentions and by a different scale of rebellions in two votes. But with Nigel Griffiths and the odd parliamentary private secretary resigning, the revolt is likely to be one of the largest apart from Iraq. Labour’s long, painful march towards realism on defence is in danger of going into reverse.

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