Prime minister co-ordinates strategy on animal rights militants as pension provider becomes latest target.

Prime Minister Tony Blair is holding secret meetings with construction industry leaders to protect firms from animal rights extremists.

Building understands that industry representatives have been brought into confidential talks with Blair, along with senior figures from universities, the police and the pharmaceutical industry. The move is partly a response to an animal rights campaign to stop the construction of a primate research laboratory in Oxford. This is now targeting construction pensions provider B&CE.

The meetings are part of an international strategy to crack down on animal rights extremists. The plans that have been developed by the UK include sharing intelligence with other countries in the Group of Eight, including the USA.

Last week six animal rights activists in the USA were convicted of inciting violence and terror by a court in Trenton, New Jersey, because of their part in a campaign against British research laboratory Huntingdon Life Sciences. This company has a laboratory in Huntingdon, Cambridgeshire, and its US headquarters is in New Jersey. Each of those convicted faces up to five years in jail.

The government also plans to work with trade associations from targeted industries, including construction, to pass advice and information to companies that fear attacks.

A spokesperson for the DTI said: "The government is determined to tackle extremists who harass or threaten those involved in life-saving scientific research. The government is committed to protecting those companies directly or indirectly involved, through the supply chain or association with it, in the use of animals in research."

News of the prime minister's intervention came as it emerged that police are investigating a letter sent to construction pensions provider B&CE by animal rights activists, warning the organisation against any involvement with the Oxford laboratory project. The letter to the organisation, which is based in Crawley, West Sussex, represents an escalation of animal rights' protest against construction organisations. The campaign had previously been limited to companies in the Oxford area.

It is understood that Brian Griffiths, chief executive of B&CE, has alerted directors, including UCATT general secretary Alan Ritchie and T&G national officer Bob Blackman, to the possibility that animal rights activists may now attempt to obtain their personal details from the directors' register at Companies House in Cardiff.

A source close to the organisation confirmed that police had visited its premises and were investigating the letter. He said: "There are two types of letters: one is polite, but I don't think this letter was polite. It warned anyone to do with construction not to have a look at the project."

Griffiths said: "We feel we have been singled out purely because we have the words building and civil engineering in our title. There is no other reason for this."

The New Jersey case was the first to be brought under the Animal Enterprise Protection Act, which now equate acts of harassment and intimidation with terrorism.