Home Secretary John Reid says he is delaying plans to merge police forces in England and Wales until the autumn.
There will be no mergers before the MPs' summer recess
He told MPs he believed mergers were still "the right way" forward, but he promised further discussions before laying any orders to enforce them.
However, the "voluntary" merger of Cumbria and Lancashire can proceed.
Tory MP Robert Goodwill (Scarborough and Whitby) welcomed Mr Reid's decision and accused the home secretary of kicking mergers "into the long grass".
The Association of Police Authorities also welcomed the statement, saying that such important issues needed to be dealt with over a reasonable timescale.
Mr Reid told MPs moves to force mergers would not be set in motion before Parliament's summer recess, which begins on 25 July.
He added: "I can't promise a referendum but I can promise discussion, dialogue and listening throughout."
The postponement was welcomed by the Tories, who want the entire controversial scheme to be ditched.
Mr Reid accepted "people want to discuss at greater length and in greater detail a lot of the questions arising from it and I have therefore decided ... that this merits further and slower consideration".
The police reform programme, begun by previous home secretary Charles Clarke, could lead to the current 43 forces being cut to as few as 17.
For the Conservatives, the shadow police reform minister Nick Herbert said: "We welcome these mergers being delayed because they were always going through on an absurdly fast timetable.
"The government now needs to stop altogether these unnecessary and expensive amalgamations that will only damage neighbourhood policing, and focus instead on the issues that matter."
Bob Jones, chairman of the Association of Police Authorities, said: "We very much welcome this opportunity to continue dialogue on the most effective approach to meeting our shared priorities of improving both protective services and neighbourhood policing."
The Cleveland Police Authority, which has opposed the merging of Cleveland with the Durham and Northumbria forces, said it was not surprised by the announcement.
Councillor Dave McLuckie, chair of the authority, said: "I do not believe anyone will be really surprised by John Reid's announcement that the original timetable laid down by Charles Clarke is to be abandoned.
"It was always unrealistic and undeliverable - and we have been trying to tell ministers and civil servants that was the case since last year."
The Welsh Assembly Government, which has complained about the pace of the merger of Wales's four forces, welcomed Mr Reid's announcement of a delay.
Wales's Social Justice Minister Edwina Hart said: "The chief constables, chairs of the police authorities in Wales and I have been pressing both the current and former Home Office ministers to review the timetable and I am delighted that they have now done so."
David Warcup, deputy chief constable of Northumbria Police, said: "In Northumbria we welcomed the opportunity offered by a single strategic force for the North East and will continue to support this process.
"The destination has been made clear but we will be seeking clarification about timescales and will be pressing ministers to give us a decision at the earliest opportunity."