In an emergency statement to a packed and sombre House of Commons, Mr Prescott confirmed that six RAF aircraft, with cruise missiles fired from the submarine HMS Splendid, had taken part in the bombardment of Yugoslavia.
Recent harrowing images from television and newspapers, with "scenes more reminiscent of the Middle Ages than of Europe on the eve of the 21st century", had proved the need to act urgently, he said.
The West was not waging a war against the Yugoslav people, but recent action by Serb forces had many comparisons with the lead-up to the Second World War, a fact that had to be "kept in the back of our minds".
"Tonight, the Nato allies, 19 nations of whom 13 flew their aircraft, has backed its words with action. It has hit hard and will continue to hit hard until the military objectives are achieved," Mr Prescott said.
"We do not expect that air attacks will lead to an instant end to the brutality in Kosovo. Yugoslavia has a substantial military machine and is under the control of a ruthless man.
"But our attacks will make it clear to President Milosevic and his security forces that if they continue to use excessive force in Kosovo they will pay a very high price indeed." He warned the Serbs that they risked being prosecuted by the International Criminal Tribunal, but also made clear to the Kosovar Albanians that they should refrain from "provocative actions".
Peter Lilley, deputy leader of the Tories, and Menzies Campbell, the Liberal Democrats' foreign affairs spokesman, offered their support.
However, MPs across all parties expressed deep unease about potential civilian casualties and the prospect of Britain being dragged into a conflict that could end with the use of ground troops. Tony Benn, (Lab, Chesterfield) said: "People who lived through the 1930s and 1940s feel a sense of utter shame and disgust that the British Government should be breaking its solemn commitment to the UN and launching air attacks upon Serbia, which was praised to the skies during the [Second World] War because it was the Serbian resistance to Hitler that gave us the opportunity of the victory we secured."
George Galloway, (Lab, Glasgow Kelvin) was jeered by most MPs when he attacked the involvement of the German air force in the Nato mission. "Given a sense of history, will you acknowledge what the effect on the psyche of the Yugoslav army and people is likely to be with the knowledge this evening that the Luftwaffe, the German air force, is in action over Yugoslav skies when hundreds of thousands of Yugoslavians were massacred by the Wehrmacht and by the Luftwaffe within the lifetime of members of this House?" he asked Mr Prescott.