Although there was widespread support among other parties for the proposals, the united Unionist front plunged the multi-party talks into uncertainty over their precise format.
But the Unionist stance had been expected, and ministers said both before and after yesterday's formal vote that the Government's determination to proceed to substantive negotiations on 15 September remained undimmed.
Tony Blair reiterated this in the Commons while the Secretary for Northern Ireland, Mo Mowlam, insisted on "all necessary steps" to ensure negotiations began on schedule.
It is now taken as a given that the two smaller Unionist parties, led by the Rev Ian Paisley and Robert McCartney, will never sit down with Sinn Fein. Most effort will therefore go into attempting to bring about a softening in the attitude of David Trimble's Ulster Unionists, which, as Northern Ireland's largest party, holds a pivotal political position.
There is speculation that the talks structure may be recast in a looser formula which might allow a combination of multi-party get-togethers and "proximity talks", with some participants maintaining a distance from the actual conference chamber.
The situation was summed up by David Adams of the Ulster Democratic party, which has loyalist paramilitary associations and which abstained from the vote. He said: "There is talk of another process. All those like ourselves who are committed to entering substantive negotiations in September will just have to put our heads down and try and come up with some other way forward."
Yesterday's development brings a potentially precarious imbalance to the peace process, with Sinn Fein set to be admitted to the September talks but Unionists hanging back. In the coming weeks some spirited debate can be expected within the Protestant community on whether its principal political representatives are right to hold back from talks. Some important clerical figures have advocated going into the talks but the balance of opinion within the general Unionist community remains to be seen.
The Democratic Unionist party's deputy leader, Peter Robinson, said yesterday: "The Government has managed to reject this process by injecting terrorists into it." Sinn Fein's response, from its chairman Mitchel McLaughlin, was to call on the Government to press ahead with talks in the expectation that those who stayed away would join at a later stage.
He said: "What we see is in fact not the exercise of consent, but the exercise of a veto ... on the political and peace process.
"It is not acceptable and it will spell for all of us a return to the conflict and the division we were hopefully about to leave behind."Reuse content