Controversial plans to merge Wales' four police forces have been confirmed by Home Secretary Charles Clarke.
Police chiefs in Wales have until 24 February to agree to a merger
At a meeting in London, he told Wales' police chiefs they had until 24 February to agree to merge South Wales, Dyfed-Powys, North Wales and Gwent.
Ian Roberts, the chair of North Wales Police Authority, who attended the meeting, called the plans "a shambles".
But Gwent Chief Supt Ian Johnstone said there could be greater local accountability after the merger.
The UK Government argues that the forces - all with under 4,000 officers - are too small to deal with major crime as effectively as their larger counterparts.
Home Secretary Charles Clarke wants a major shake-up of policing
Plans for the radical restructuring of the 43 forces in Wales and England were revealed last September when the Inspectorate of Constabulary described police structure as no longer "fit for purpose".
It said smaller forces were not best placed to meet the challenges of 21st Century policing such as terrorism and cross-border crime.
Confirming his plan on Monday, Mr Clarke said a single force for Wales was the "only one acceptable option".
He said: "My vision is a police service which is close, responsive and accountable to the communities it serves, supported by larger forces with the capacity and specialist expertise to protect the public from wider threats such as serious and organised crime and terrorism."
But such a vision has been fiercely resisted by some police authorities and MPs who believe that the performance of the forces reflected their ability to carry out their role effectively.
Mr Roberts said: "We are extremely disappointed that the home secretary appears determined to break the promise made by the prime minister.
"Mr Blair pledged in the House of Commons that no police mergers would be 'forced through'. Now Mr Clarke says he wants to do exactly that.
"What's even more puzzling is that last week Mr Clarke said he would consider the possibility of North Wales Police merging with our counterparts in Cheshire.
"That idea has never been on the cards as far as we are concerned - all we've ever said is that we'd like to look at the possibility of building on existing collaboration.
"But all this confusion gives the impression that Mr Clarke is totally at sea over this issue. Quite frankly, it's a shambles."
He said the police authority would convene a special meeting on the issue.
Mr Clarke told Wales' police chiefs that if they did not agree by 24 February to merge into a single all-Wales force, he would press ahead with the changes anyway.
The Home Office said that if three forces agreed to merge, and the North Wales Police did not, then an amalgamation could still go ahead, with the remaining force given the option of joining later. Ministers want the changes to take place within 12-18 months.
Chief Supt Ian Johnstone, vice-president of the Police Superintendents' Association of England and Wales, backs the plans.
He said: "If we have less local accountability at the end of this, the merger will have failed but there is no reason at this stage why we should lose this local accountability and, in fact, if we get it right, it should be strengthened."