LANCASHIRE police spent £1.8million investigating a plot to blow up aircraft - as bosses also revealed they were monitoring more than 40 people with suspected terrorist links.

Acting Chief Constable Steve Finnigan revealed the figures as he made a pitch for extra government funding due to such new pressures on his budget.

The national anti-terror operation - codename Overt - resulted in the security clampdown at all major British airports in August.

Mr Finnigan said his force spent £1.8million on its part in the covert operation.

He revealed for the first time that his officers had made arrests in the county as part of a Metropolitan Police raids which saw detentions across the country.

So far 17 people have appeared in court across the country in connection with the plot but none are believed to be from Lancashire.

And Mr Finnigan also revealed that there were more than 40 Islamic extremist terrorist suspects living in Lancashire who were being monitored by the security services.

The developments came to light at a Lancashire Police Authority meeting in which members called on central government to help pay the £17.6million extra they believe is needed to police the county.

This would be a 7.3 per cent rise in the force's £240million budget.

But despite the plea, Local Government Minister, Phil Woolas, said the force was likely to get the standard rate of 2.7 per cent extra in its funding for the next financial year.

Police bosses now face having to dramatically increase council tax to fund the £17.6million shortfall, or find ways of making savings to balance the books.

Mr Finnigan told the meeting that the head of MI5, Dame Eliza Manningham-Buller, had said that the security service knew of 30 plots by Islamic extremists and had identified 1,600 people plotting actively, or facilitating, terrorist acts.

He added: "Lancashire has got more than its fair share that we feel the need to look at in relation to international terrorism."

After the meeting, when asked for the number of suspects, he said: "I am not going to go into details, but if you want to divide the number equitably across the country's 43 police forces we have more than the average.

"We are looking at these people to find out what their intentions are and what their capabilities are."

Following the revelations, terrorism expert Dr Nick Megoran, of Newcastle University, said there were two main factors behind the rise of terror plots.

He said: "British foreign policy in Iraq and Afghanistan have provided a grievance that mobilised Muslims in Britain.

"But most Muslims are not terrorists and do not support terrorism.

"But foreign policy on its own has not been enough. You have had a network of recruiters in Britain linked to abroad - places like Saudi Arabia.

"Al-Qaeda have manipulated the concerns, fears and legitimate grievances to convince them there's a war going on between the West and Islam."

Ethnic minorities make up about 10 per cent of the population in Lancashire and 4.7 per cent of the county's inhabitants are Muslims.

Mr Megoran said he did not know why the numbers of suspected islamic extremists were higher in Lancashire than in other areas.

But he said that the prominence of high-profile Blackburn MP, Jack Straw, who was foreign secretary when the wars in Afghanistan and Iraq started, could have been a factor.