Stephen House, the chief constable, has been plunged into a turf war over who manages key services such as human resources, IT and finance. Mr House is said to be "spitting nails" at a bid by the Scottish Police Authority (SPA), the body set up to scrutinise the force, to take over the behind-the-scenes functions before the force goes live on April 1, 2013.
He has already won the support of the Association of Scottish Police Superintendents (ASPS), which said Mr House was at risk of being made "subservient" to SPA chairman Vic Emery.
Chief Superintendent David O'Connor, the ASPS president, said: "We cannot support a position where the SPA may seek to give direction to the chief constable in relation to any matter relating to operational policing.
"This would fundamentally erode operational independence with all the dangers this brings to a democratic society."
Mr Emery, a former senior adviser on the ill-fated Edinburgh tram project, insisted he had not made any specific proposals about his organisation taking over functions currently carried out by Scotland's existing eight territorial forces.
In a letter to MSPs, Mr Emery said he was looking for a way to allow Mr House and his team "to concentrate their focus on policing".
Mr Emery added: "What we have indicated in our early discussions with the chief constable is that the conventional arrangements where all support functions and staff are automatically within the direction of the chief constable require to be considered differently."
The letter was a response to a parliamentary motion by Labour MSP Graeme Pearson, a former head of the Scottish Crime and Drug Enforcement Agency (SCDEA). He expressed deep concern about "the way the operational independence of the Police Service of Scotland is being undermined".
Mr Pearson, who quit the agency in December 2008 after a row over interference by the Scottish Police Services Authority (SPSA), called the proposals "unwarranted".
The SPSA, which was later chaired by Mr Emery, handled human resources, finance and other back-office functions for the SCDEA.
Mr Emery has insisted this helped contribute to the agency's success in recent years and suggested this model should be replicated.
But police insiders believe such a move would tie Mr House's hands operationally. One officer asked: "How can the SPA seriously be considered a watchdog if it itself is doing a lot of the work it is supposed to be overseeing? And how can the chief do the job he needs to do – including possible cuts and tough decisions – if he doesn't control HR and finance?"
The Herald understands Justice Secretary Kenny MacAskill has been forced to act as a peace broker between Mr House and Mr Emery.
A Scottish Government spokesman said the law that paved the way for the single force clearly set out the responsibilities of the SPA and the Police Service of Scotland. He said it was up to Mr Emery and the rest of the board "in close dialogue with chief constable" to decide how best they should fulfil those responsibilities.
He added: "They have not yet reached
any conclusions on these issues, nor have any formal proposals been brought forward."
Alison McInnes, LibDem justice spokeswoman, said: "We repeatedly warned of the dangers of political control and the loss of local accountability for the very reasons Mr Pearson mentions."
Tory Chief Whip John Lamont said: "We do not share the bulk of concerns set out in this motion. However, we will be keen that a close eye is kept on the Scottish Government as it implements the single force."
The Scottish Police Federation last month said it would regard any bid for the SPA to carry out executive functions of the single force as a "source for conflict".