The government has unveiled plans for tougher sentencing for animal rights activists who terrorise scientific researchers.

However ministers appeared to be at odds over the proposals, with some suggesting the new powers of house arrest for foreign terror suspects could be extended to anti-vivisection protestors.

Industry secretary Patricia Hewitt published plans on Monday for punishments of up to five years in jail for activists found to have intimidated or assaulted scientists, their families or facilities.

Outlining additions to the Serious Organised Crime and Police Bill, she said the government is determined to make Britain a safe country in which to conduct research.

Ministers are keen that inward investment is not deterred by the threat of protest groups and that vital medical research is able to take place.

But the announcement was hit by the apparent contradiction of ministers who are either in dispute over or unaware of each others' intentions.

Confusion

Home Office minister Hazel Blears last week said that her department's plans for house arrest of terror suspects whose cases have not come to court could be extended to include the extreme wing of the animal rights lobby.

"What we are saying is, if there is a serious threat from terrorists who would threaten this country... then we should respond to that," she said.

Foreign secretary Jack Straw told the BBC that he backed the move on Monday.

"I know some of the people who have been the victims of this so-called animal rights terrorism," he told Radio 4's Today programme.

"It is terrible and these orders, when they are introduced - [home secretary] Charles Clarke has my full backing for them - are the minimum that is required if we are to have scientific research that saves people's lives in this country."

However Hewitt told the same show that this was not the case.

"My understanding is that what we are proposing to do in relation with international terrorism is restricted to international terrorism," she said.

"I see these as separate issues and I think the law we are proposing this morning for animal rights extremists is proportionate.

"I think it is the right response to what, I am afraid, has become a growing problem which is threatening to destroy a very important part of medical research in our country."