The British Prime Minister, Mr Tony Blair, yesterday promised to do "whatever is necessary" to track down the bombers as London prepares to toughen its antiterrorist legislation in line with measures announced by the Government this week.
The proposals under consideration, outlined by the Northern Ireland Secretary, Dr Mo Mowlam, on Monday, include making it easier to convict people for membership of proscribed organisations such as the so-called `Real IRA', enhancing cross-Border co-operation between the RUC and the Garda and other unspecified security measures.
The proposals were discussed at a meeting of the cabinet in Downing Street yesterday, and the possibility of recalling parliament has not been ruled out. A Downing Street spokesman said the British government hoped to move forward in step with Dublin without the need for primary legislation.
Mr Blair spoke with the Taoiseach, Mr Ahern, by telephone from France, where he is on holiday. Afterwards, he insisted both governments were united in their determination to ensure the people responsible for the bomb were "dealt with and taken off the streets".
Mr Blair said the measures unveiled by the Government indicated Dublin was "true to their word". He said co-operation between the governments was now unprecedented.
"The complex legal and technical issues are being urgently addressed. We will bring in similar measures to those proposed by the Irish Government so that then we will have the toughest antiterrorist measures in the whole of the island of Ireland that we have ever seen."
The British government can introduce the security measures in a number of ways. It may decide to introduce the proposals under primary legislation, which would require parliament to be recalled, or it could issue a ministerial order under existing anti-terrorist legislation, either the PTA or the EPA.
The question of whether parliament would need to be recalled in this instance would depend on the provisions contained in the PTA and the EPA enabling the order to be introduced into legislation.
An order in council, signed by Queen Elizabeth, could also be issued in parliament without recalling MPs or peers, with retrospective approval being sought within 40 days.
The Northern Ireland Minister, Mr Paul Murphy, was equally tough in his determination to strengthen anti-terrorist legislation, describing the proposals as a "formidable array of measures" when speaking on BBC Radio 4.
However, the Labour MP, Mr Jeremy Corbyn, said the measures under consideration were unnecessary. "It could create further miscarriages of justice and it could create further martyrs. We need to continue with the peace process and defeat these people politically."
The Shadow Northern Ireland secretary, Mr Andrew Mackay, said his party would support new anti-terrorist legislation. "I believe our security forces must be able to tackle terrorism with every tool available."