Sir Norman Bettison, the Association of Chief Police Officers' head of future developments, told an influential committee of MPs that the merger of police forces in England and Wales to create larger forces is "inevitable".

He believes that just one high-profile mistake or error by a force could trigger renewed calls to resurrect the idea of larger strategic police forces.

He said: "The reason I say 'inevitable' is I predict that it is events that will bring this back to the agenda.

"It will be the failing of a force to do what is required in the 21st century that will cause people to ask whether it is suitably equipped, whether it has got capacity/capability to meet the demands."

Merger plans were put forward in 2005 by former Home Secretary Charles Clarke, who aimed to reduce the number of forces in England and Wales from 43 to around 24.

The aim was to create forces that were better able to tackle the threats of terrorism and organised crime.

Lancashire and Cumbria were the only forces in the country to voluntarily move towards the merger plans.

It was estimated that the merger would have led to savings of £5m a year, but the proposal was eventually scuppered following a row over council tax bills.

Eventually, Mr Clarke's successor, John Reid, pulled the plug on the whole policy.

However, Mr Bettison told MPs on the Home Affairs select committee that it was becoming "more and more untenable" for each of the 43 forces "to be technologically equipped and ready to support a police service in the 21st century".

Today Lancashire Police Authority and Lancashire Police Federation (LPF) maintained its support for the plans and welcomed the discussions.

Steve Edwards, chairman of LPF, said: "A recent review says as long as forces maintain their local identities there are advantages into becoming a larger force.

"For our members, there would be increased working opportunities. The workforce would be increased from around 3,500 to 5,000 so there would be other roles for people to get into.

Malcolm Doherty, chairman of LPA, said: "We would approach it like before, wanting whatever is best for the people of Lancashire. We think it is in the interests of people in Lancashire and Cumbria."

But Ribble Valley MP Nigel Evans, said: "They are clearly not listening to the public. We know the public like to see their police organised in the divisions that are currently there."

Lancaster and Wyre MP Ben Wallace, said: "He (Sir Norman Bettison) forgets that we are policed by consent in this country.

"The reason it failed was that the government tried to do it over the heads of public opinion."