Controversial plans to merge Thames Valley Police have suffered a setback after it emerged that the timetable for the restructuring has been set back.

Home Secretary Charles Clarke had promised to respond to police forces' recommendations this month.

But the Home Office has revealed that talks over the proposed mergers will run into next month at least.

There would be no final decisions until the spring, a spokesman added.

The hold-up emerged as Prime Minister Tony Blair paved the way for the proposals to be watered down, by raising the prospect of loose regional federations of forces.

Mr Blair suggested forces might only be asked to work together in certain areas -- a proposal dismissed out of hand by Mr Clarke before Christmas. Amid opposition from police authorities and the public, Mr Blair told MPs last week that it was "important we listen to local people".

He added: "There are many different things that could happen, including forces coming together for certain strategic tasks which they are better able to fulfil on a common rather than singular basis."

Last September, Mr Clarke ordered forces to draw up merger plans to meet new criteria that each force had at least 4,000 officers. Thames Valley meets this requirement, but neighbouring Hamp- shire, suggested as a possible merger partner, does not.

Plans had to be submitted by the end of December, after which Mr Clarke said he hoped to respond in January. But the Home Office said issues remained to be resolved with chief officers and police authorities.

The Acting Chief Constable of Thames Valley Police, Sara Thornton, said: "We were always told it would be February, so it doesn't surprise me. It would be really good from the force's point of view if it was earlier, but to be fair it was supposed to be February."