Northern Ireland Secretary Dr John Reid said this evening the car bomb which exploded in West London last night was attempt to derail the peace process by people who had no democratic mandate and who were defying the clear will of the people.
Dr John Reid said: "It achieved no purpose other than to remind people of what they were trying to escape from."
"Far from deflecting us, this barbaric attack should strengthen our resolve to reach agreement. No one will understand if we allow the solution that is within our grasp to slip away," he added.
The bomb is believed to be the work of dissident republicans, Scotland Yard said.
The bomb attack, which injured seven people when it went off at Ealing Broadway shortly before midnight, was described as intending to "kill or maim" by Deputy Assistant Commissioner Mr Alan Fry.
The Taoiseach condemned the bombing in a statement added: "these acts will not deter both Governments, the pro-agreement parties and the overwhelming majority of people who seek peace on this island.
"We utterly reject the motives of those responsible and will not allow them to thwart the progress in resolving all outstanding issues in the peace process."
The Minister for Foreign Affairs Mr Cowen extened the Government's sympathies to the injured in "this senseless act".
UK police said today they were hunting a man with a pock-marked face who they believe bought the car used in the bomb attack.
The car had been purchased at Green Lane in Ilford, east London, Mr Fry told a news conference at Scotland Yard.
It also emerged that police were called to examine the car, a grey Saab 9000, by members of the public on Monday.
The vehicle appeared to have been abandoned, but police took no action because it had not been reported stolen or was suspected of being involved in terrorism, he said.
Police also described how they were given just 27 minutes to locate and deal with the bomb which went off injuring seven people.
Mr Fry said: "This is a completely reckless terrorist attack."
"Police were not given a correct and precise location of the car bomb. No time of detonation was given. The time between the call and explosion was very short. This lack of information shows a disregard for lives".
Mr Fry said a threatening phone call was made at 11.33 p.m. last night and a search of the area was conducted within minutes.
He said the explosion had been planned to maim and kill young people and was a "calculated evil deed".
He said: "The scene is still being searched but we have found fragments of blue plastic from a barrel-like container.
"This is similar to the one used to transport the BBC bomb and also ones in Ireland."
The device exploded near a pub around 100 metres from the Tube and railway station at around midnight.
Seven people were taken to hospital and four were admitted. None of the injuries was thought to be life threatening, according to hospital staff.
Eyewitnesses said the explosion occurred near The Townhouse pub in Uxbridge Road, just as the area's bars were emptying.
Sinn Féin chief negotiator Mr Alex Maskey said the bombing placed greater emphasis on ensuring the Belfast Agreement is implemented.
He told BBC Radio 4's Today programme: "It simply reaffirms that there is a small microrepublican organisation which is opposed to the peace process and that is, of course, nothing new.
"What it tells us is that we have a major responsibility on ourselves, all of us, that includes the Government, to implement the Good Friday Agreement which is what people in very high numbers voted for - that's what we've got to do."
PA