Police chiefs are due to begin talks over potential mergers in response to plans for a shake-up of forces.

The plans, which are backed by Home Secretary Charles Clarke, will mean the creation of large strategic forces to be better able to cope with modern threats such as terrorism and international drug trafficking.

Last night, the head of Cleveland Police Authority, Councillor Dave McLuckie, said he was assembling a small team to look at options for his force with the aim of coming up with proposals by December.

North Yorkshire Police Authority also said it would try to engage in discussions with neighbouring police forces and authorities over the next three months, in response to the call to slim down the present national structure of 43 police forces.

Meanwhile, it emerged that mock-up maps showing suggested mergers between forces were on display at a meeting in London of chief constables and police authority chairmen and women, attended by Mr Clarke.

These showed Cleveland joining one or more forces in Yorkshire and Humberside.

Another suggestion understood to have been put forward at the meeting was that Cleveland would effectively be divided into two.

Its more urbanised northern portion and the rural south of the force area would split and join other police forces.

A merger between theCleveland and Durham forces has also long been speculated about, but has previously been dismissed.

Last night, Coun McLuckie said: "Changes are going to happen. It is a fait accompli and there are only the exact mechanics to discuss.

"As far as we are concerned we have got to make sure that we achieve something that is best for us, whether that is being left alone or trying to merge with Durham."

Jane Kenyon, chairwoman of the North Yorkshire Police Authority, said: "In principle, we support what the Home Secretary is seeking to achieve and we will work tirelessly to analyse whether any different structures or other arrangements would deliver benefits to our communities."

The planned shake-up was prompted by a report from Her Majesty's Inspectorate of Constabulary by former Surrey chief constable Denis O'Connor.

The report said smaller forces were not well positioned to respond adequately to serious crime and other major incidents, such as terrorism and natural disasters.

It added that forces with more than 4,000 police officers tended to perform best.

At present, 36 forces are below those manpower levels, and 19 have fewer than 2,000 officers available for duty.

These include Cleveland with 1,772, Durham (1,700) and North Yorkshire (1,566).