Some 60,000 people, from shopping centre security guards to hotel workers, are being trained to respond to the threat of terrorism, Home Secretary Jacqui Smith said.
Her comments came two days ahead of the publication of a counter-terrorism strategy which ministers are billing as the most comprehensive approach to tackling the threat issued by any government in the world.
PM Gordon Brown issued a warning that the public must remain "vigilant at all times" to the threat from al Qaida terrorists, who he said were "intent on inflicting mass casualties without warning, including through suicide bombings".
Writing in The Observer, Mr Brown said: "Today, not only the police and security and intelligence officers and our armed forces, but also the emergency services, local councils, businesses and community groups are involved in state-of-the-art civil contingency planning."
He said there was a "duty on all of us" to stand up to people who advocate violence and preach hate.
"Terrorism threatens the rights that all in this country should hold dear, including the most fundamental human right of all - the right to life," he said.
"We know that terrorists will keep on trying to strike and that protecting Britain against this threat remains our most important job."
Ms Smith told BBC1's The Politics show that the document being published by the Home Office on Tuesday - known as Contest Two - would provide "a complete strategy to address counter-terror".
She said that ministers were determined to be open about the steps they are taking to prevent people turning to extremism, to track down and detain those involved in terror plots, to protect British citizens and UK interests against attack and to deal with the consequences of any outrage.
