Why can you join the Labour Party in Baghdad but not in Belfast?

The time has come to move on from the Good Friday Agreement and for the British parties to organise in Northern Ireland

For the fourth time since the 1998 Good Friday Agreement, the Northern Ireland power-sharing executive and assembly have been suspended. Direct rule, under a benign colonial governor in the shape of John Reid, is back. In terms of the day-to-day governance, nothing much will change. Schools, hospitals, agriculture and other devolved responsibilities will carry on much as before, although they will now be run by British government ministers rather than home-grown Northern Irish politicians.

Moreover, power-sharing is only one of the pieces in the jigsaw. The arrangements between the United Kingdom and Dublin, and the institutions between Belfast and Dublin, will be largely unaffected. To this extent there has still been a net gain from the process, which, when originally embarked upon by Sir Patrick Mayhew and John Major, was always envisaged as more than just power-sharing.

So the Good Friday Agreement has not entirely been a waste of time. The Irish Republic surrendered its territorial claim on Ulster and, in return, the British Government acknowledged the right, should a majority ever wish it, of Ulster to become a part of the Republic. Whatever difficulties lie ahead during the forthcoming indefinite period of suspension of the executive, there does not have to be any need for the roof to fall in. But it is clear that, ultimately, power-sharing between two fundamentally opposed traditions is the rock on which the peace process succeeds or fails. "There is no other show in town," say its supporters. However, each time a suspension occurs, the prospects for the long term take a significant knock.

The worst outcome of the latest suspension would be a polarisation between the two traditions, with both Sinn Fein and Ian Paisley's Democratic Unionists profiting in terms of popularity at the expense of the moderate SDLP nationalists and David Trimble's Ulster Unionists. If the suspension lasts for months, rather than weeks, it may even be necessary to defer the assembly elections, which are scheduled for May. Alternatively, Mr Reid could call for immediate elections. Sinn Fein and the Democratic Unionists would be the principal beneficiaries of such a move, and the prospects for power-sharing even more remote. Mr Reid is right not to take this option, and direct rule is, in the circumstances, the least bad option.

But what if direct rule is still in operation beyond next May, when the elections would otherwise have been due? It is surely impossible to have an election to a body that is in suspension. The conclusion, however unpalatable, has to be reached that local power-sharing simply may not work again in its current form. What is becoming apparent is that this system of government only works if the voters do the "right" thing. It is not designed to cope with Sinn Fein and Ian Paisley's Democratic Unionists winning the largest blocks of nationalist and Unionist votes.

That always seemed to me to be one major failings, one that the founding fathers of the agreement never addressed: how to give the people of Northern Ireland, whatever their religious and territorial sympathies, a stake in the electoral process enjoyed by the rest of the voters in the UK.

The biggest affront to all the voters of Northern Ireland was not the extent to which they had no say in their local administration, but the fact that they have never had any input into the election of a national government. They may love Tony Blair – or loathe him. They may be screaming out for "the quiet man", Iain Duncan Smith. They may even yearn for Charles Kennedy. But however much they are interested in British politics, and whatever their views on taxation, on the third way, on the Tories' 25 new policy initiatives or on Iraq, they have no opportunity to vote Labour, Conservative or Liberal Democrat. In short, they are denied the ultimate political power of deciding, as the rest of us do, who the occupant of 10 Downing Street should be.

The voters of Scotland and Wales, even with their own devolved parliament and assembly, still have a direct stake in the election of a Labour or Conservative government. Indeed, it can be said that they have a disproportionate influence on national politics.

At various times in the past there have been links between the Tories and the Ulster Unionists. In the government of Harold Macmillan, there were even ministers recruited from the Unionists. But the splintering of the relationship during Edward Heath's premiership has meant that in parliamentary terms, apart from a vague general sympathy for Unionism, the Tories have no way of testing their support in Northern Ireland. There is an informal relationship between Labour and the SDLP of John Hume and Mark Durkan, but there is little feeling, generally speaking, that it is able to garner votes from Protestants who would wish to see a Blair government elected.

What does the Catholic voter in Londonderry who yearns for Mr Duncan Smith to be Prime Minister do? And, similarly, what does the trade unionist who is Protestant and working class do if he wants to vote for Tony Blair?

Northern Irish politicians are condemned to play a part only in sectarian politics. Anyone from the province who believes they have the skills and ambition to partake in the truly national debate is required to leave Northern Ireland. So Brian Mawhinney came to England, where he represents a Cambridgeshire seat for the Tories, while the Liberal Democrat Lembit Opik represents a Welsh constituency. Politicians of the calibre of John Hume or David Trimble have been unable to realise their true potential as cabinet ministers serving the whole of the UK.

The time has come, during the current interregnum, for the three British-based political parties to offer all the voters of Northern Ireland a stake in the choice of the national government. The Tories made a tentative attempt, over a decade ago – before the peace process began – to put up candidates in some Ulster constituencies but ran into difficulties with the Unionists. They subsequently lost interest in the idea. Some in the Labour movement are still pushing for change. John Edmonds, the GMB general secretary, has said that his union will take the Labour Party to court over its refusal to allow people in Northern Ireland to become members. As Mr Edmonds rightly said: "It's outrageous that you can join the Labour Party in Baghdad but not in Belfast."

The Good Friday Agreement needs to be taken on to the next stage in the "normalisation" of the political process. The dual mandate for the Scottish and Welsh assemblies has now been abolished. That could be the way ahead for Northern Ireland to break out of sectarian politics. Let no one in the Belfast assembly stand for Westminster, but, in return, give Northern Ireland the chance to vote for national parties, enabling voters to have a stake in the government of the United Kingdom.

mrbrown@pimlico.freeserve.co.uk