The most wide-reaching centralisation of the police service in Scotland in a generation is being proposed by one of the government's top advisers.

In a confidential report obtained by The Herald under the Freedom of Information Act, Malcolm Dickson, assistant inspector of Her Majesty's Inspectorate of Constabulary (HMIC), proposes that a huge range of police roles be stripped from Scotland's eight regional forces, which could particularly affect the Strathclyde force.

Instead the policing of Scotland's motorways, VIPs, serious fraud, counter-terrorism, air support, investigating police corruption and firearms would be under the authority of the new Scottish Police Services Authority (SPSA).

Scotland's chief constables are understood to be strongly opposed to many of the proposals which could leave forces dealing with little more than low level offending and volume crime such as housebreaking.

Steve House, Chief Constable of Strathclyde Police, the biggest of Scotland's police forces, said: "Our only concern in all of this, is to provide the best policing for the people we serve. The report itself makes it clear that the public in Strathclyde would get a lesser service under these proposals. For this reason, I have opposed the proposal and I will continue to do so. Strathclyde Police has been recognised as a strategic force - in other words it can stand on its own.

"The SPSA is portrayed as a solution to the needs of Scottish forces, but it is not a solution for Strathclyde Police - the HMIC in Scotland has said as much in this report.

"We do not believe that the transfer of operational functions to the SPSA is the only or best national solution."

In an article in today's Herald, Graeme Pearson, the former director of the Scottish Drug Enforcement Agency, says that many of the areas identified for transfer to the SPSA would be difficult to reconcile with the remit laid down for it by the Scottish Parliament.

He also points out that, since the SPSA has yet to publish its first annual report it is impossible to establish "its effectiveness in the discharge of its current responsibilities". As a result, it makes a judgment on transferring additional services "extremely difficult to make".