It is nearly a year since the establishment of Scotland's single police force and today, in an interview with The Herald, its Chief Constable Sir Stephen House mounts a strong defence of it.

"We have established a national police force fit for a Western democracy," he says. "I am very proud of the work police officers and staff have done."

However, there are still some issues that remain unresolved. One of the most serious is the concern that a Glasgow-centric approach is being imposed across the country - one which, it is alleged, removes the ability of officers to respond to local problems in the most appropriate way. Critics have suggested this is what happened in the case of the Edinburgh saunas, which were tolerated by the Lothian and Borders force but are being shut down by Police Scotland.

Then there is the issue of accountability and the extent to which elected representatives can scrutinise the new force. Before the amalgamation, there were eight police boards responsible for holding all the forces to account. Now every local authority has a different and often less formal structure in place to work with local commanders. There was also a turf war between the new force and the Scottish Police Authority - one which the force won.

In his response to these concerns, Sir Stephen says policitians may be out to prove a point but he is also robust in his reaction to the claims a Glasgow-centric approach is being imposed.

In the case of the saunas, Sir Stephen argues the force is keeping women safe and its actions are based on criminal warrants. There is also an argument for national consistency even though concerns about the ability to respond to the needs of local communities will linger. One of the potential benefits of a consistent approach can be seen in the figures on crimes arising from domestic abuse in Edinburgh, which are up by 138%. Clearly, the old force was not pursuing many of these cases that were being pursued in Glasgow and it is right that this anomaly has been fixed.

As for accountability, there is still a large degree of flux and uncertainty, which should have been resolved 12 months in. Sir Stephen says he is pleased with his relationship with the SPA and in theory making a local police commander directly answerable to each of the 32 local authorities should increase rather than diminish local accountability. But the Scottish Government will have to keep a close watch on this new, more informal, less visible structure and it remains to be seen whether the balance has shifted too far in the direction of operational autonomy and away from governance.

There is also the persistent fear the creation of Police Scotland has created a force too big to respond swiftly and appropriately to local needs. This week, a reader of The Herald related how he was passed from station to station over several weeks after his car was damaged. Such cases do not help the force's image but, in principle, there is no reason why it cannot police a wide, variable area in the way many of the old forces did. Police Scotland remains a good idea but, a year in, there are still questions about whether all the right structures are in place.