The news of elections was widely blamed for derailing the peace process, but terrorists carried out a dummy run with the Ford lorry eventually used to carry the bomb more than three weeks before it exploded in London on 9 February.
Scotland Yard said yesterday that an IRA team arrived on a ferry at Stranraer in Scotland on 15 January and are thought to have driven the lorry along the route which they took to carry out the attack at South Quay, which killed two people and injured over a hundred. They returned to Ireland the next day.
Commander John Grieve, head of Scotland Yard's Anti-Terrorist Branch, said yesterday: "Because it was under its complete, final, covert identity, it looks that it was a reconnaissance or dummy run to see how far they could get away with it."
Speculation suggested that the bombing was the IRA's response to John Major's announcement that elections would be held. The plan, unveiled by the Government following the Mitchell Report on the peace process, was blamed for provoking an end to the ceasefire.
But the Mitchell Report, which said there was no realistic prospect of the paramilitaries agreeing to the Government's demand to give up their weapons before all-party talks, was published on 24 January.
The dummy run, more than a week before, shows that IRA contingency plans to bomb London were more advanced than previously thought. They may have planned to end the ceasefire regardless of the Government's reaction to the report.