Plans for a crackdown on animal rights campaigners who use terror tactics against scientists have been unveiled by the home office.
Existing legislation will be amended
Protesting outside someone's house in an intimidating manner will be made a specific criminal offence.
Harassment laws will also be tightened up and special prosecutors appointed for each police area.
It follows concern the economy is being harmed by the security costs firms face in dealing with such activism.
Home Office minister Caroline Flint said the strategy was to tighten up and amend existing legislation - rather than create a separate bill to deal with the problem.
"We will be strengthening the powers of the police to tackle protests outside family homes because it's not just about the impact on the person targeted but the whole family," she told BBC Radio 4's Today programme.
"What we are talking about here is an extremist campaign attacking people for doing activities which are guided by the law," she added.
She said the UK had the "strongest laws in the world" on the use of animals in research and people were being attacked "for doing nothing illegal".
Ms Flint dismissed a suggestion that troops might be used to guard a new research laboratory in Oxford, saying:
"There are no plans for members of the armed forces to assist in that way at all."
Some research staff have faced hate mail, threats and terrifying 'home visits' from protesters.
Brian Cass, managing director of Huntingdon Life Sciences, one of the animal testing firms targeted by extremists, said protests at scientists' homes had caused "considerable alarm".
"Any strategy which prohibits home demonstrations is welcomed," he said.
Although there were already laws to deal with many of the tactics used, police in 50 different forces had not viewed the activism as a national campaign, he said.
The plans also come as animal rights campaigners lost a High Court battle to overturn a decision to grant planning permission for a primate research centre at Girton near Cambridge.
Under the strategy, it will become an arrestable offence to protest outside someone's home in an intimidating manner and those guilty of doing so will be banned from the vicinity of that home for a three month period.
This will be brought in by amending the Criminal Justice and Police Act 2001.
Anti-stalking legislation in the Protection from Harassment Act is being extended so that it can be used to safeguard a group of employees, rather than simply a named individual.
A national forum of 43 specialist prosecutors has already been set up, with one for each of the police force areas in England and Wales.
They are likely to draw up battle plans with police.
A specialist police unit, located in the National Crime Squad, has been created to target leading organisers of violent animal rights protest.
Law enforcement agencies will also be urged to make a "more concerted use of existing powers" such as antis-social behaviour orders in the fight against animal extremists.
Calls from the bio-tech industry for a single piece of legislation to tackle the issue - rather than the string of amendments announced - were rejected by the home office.
"We have not closed the door on this but it would not be sensible to try to seek a separate Bill which because of the pressures of parliamentary time could not be taken this year," the home office strategy paper says.
Shadow home secretary David Davis welcomed the new laws but said they need to be "vigorously enforced".
"The CPS and the police must cooperate to ensure people responsible for this behaviour are brought before the courts and dealt with," he added.
Andrew Butler from the animal rights group, People for the Ethical Treatment of Animals (Peta), said the government was "demonising" animal rights activists by treating them with a very "broad brush".
There were already laws to deal with illegal activities and public order offences, he said.
The new laws simply "singled out animal rights activists" and would prevent them from "uncovering" what was going on in laboratories, Mr Butler added.
Heather James, a member of the anti-vivisection pressure group Stop Huntingdon Animal Cruelty (SHAC) said the new measures would not stop people breaking the law.
"People who break the law know the risks they are taking. Changing the law is not going to make any difference.
"They should be looking at what the labs are doing, rather than turning their attention to us."