Britain is back on anti-terrorist alert as the hours tick away to Mr Tony Blair's expected announcement of a general election for June 7th.
The Prime Minister was back in Downing Street last night after celebrating his 48th birthday with his family at Chequers. This morning he will preside over a "political" cabinet to formally approve Labour's manifesto.
Soon after - possibly as early as tomorrow morning - Mr Blair is expected to travel to Buckingham Palace for an audience with Queen Elizabeth. There he will formally seek the dissolution of parliament, so clearing the way for the election and Labour's bid for an unprecedented second full term in office.
Despite Labour's commanding lead in the opinion polls, Mr Blair will tell ministers they must "fight the election as if it is on a knife edge".
And the Conservative Party chairman, Mr Michael Ancram, has dismissed predictions of an increased Labour majority, insisting that the votes of just 3,000 people in 180 target seats could put the Tories back in power.
But as election fever gripped Westminster, the latest bombing attack on a postal sorting depot in north London heightened fears that dissident Irish republicans are intent on disrupting the campaign.
Only one person was injured in the blast at around 1.40 a.m. yesterday, in what police believe to be the second "Real IRA" attack on the Hendon depot in less than a month and the sixth bombing attack by that organisation in the capital in just under a year.
Deputy Assistant Commissioner Alan Fry said the device, containing about half a pound of high explosives, would have been sufficient to cause serious injuries or even death. He warned the British public to be extra-vigilant as the election campaign grew closer.
Noting the sustained actions of the Provisional IRA during the 1992 and 1997 campaigns, Mr Fry said of the current dissident republican threat: "We take note of that and will be doing everything possible to secure the safety of those taking part in the election and of the general public."
However, as forensics experts scoured the scene of the blast for clues to the identity of the bombers, Mr Fry said: "Unfortunately we are looking for a needle in a haystack, and you cannot hope to be able to prevent any outrage such as this."
The Northern Secretary, Dr John Reid, has led the condemnation of those behind the latest bomb attack. However, he said it would serve only to strengthen support for the Northern Ireland peace process.
"I utterly condemn what has happened. The people that carried this out have no support, no sympathy, and will be universally condemned. They have no strategy other than to try to wreak murder and mayhem in order to bust apart the peace process," Dr Reid said. Northern Ireland's First Minister, Mr David Trimble, coupled his condemnation with a suggestion that Sinn Fein might also wish to see the Belfast Agreement collapse, and that the Provisional IRA had been involved in two recent murders.
Mr Alex Attwood of the SDLP stressed that pro-agreement politics was stronger than the forces threatening it.
"No doubt if these attacks continue they will serve to heighten tensions during the elections. But the North has come through periods of heightened tensions before and we can do so again," he said.