She added, in reply to a Parliamentary question on Tuesday, that HLS was a leading provider in the highly regulated area of essential research, development and toxicological testing services for the pharmaceutical, biotechnology and chemical industries.

"Any commercial damage to these industries would have a very serious impact on UK scientific and medical research," she said.

The move follows a campaign of intimidation by activists against insurance brokers Marsh & McLennan in both the U.S. and Britain in an attempt to force it to sever links with HLS.

Last year the government provided banking services to the company after its own bankers withdrew their services following intimidation by animal rights activists.

After repeated attacks on its staff and threats to shareholders, the company - based near Cambridge in eastern England - delisted from the London Stock Exchange and moved its headquarters to the United States.

The government has since brought in new laws to protect companies from violent protests.