GlaxoSmithKline (GSK) has insisted the company will not be driven overseas by animal rights campaigners.
Activists threatened to 'name and shame' GSK investors
Chief executive Jean-Pierre Garnier warned that the UK economy needs more than one international player in the drugs market.
He also called for tougher action from the police to limit the activities of animal "extremists".
His comments came a week after the firm won an injunction against activists who threatened GSK investors.
The company hit the headlines last week when the Campaign Against Huntingdon Life Sciences warned shareholders to sell their stakes or face having personal details revealed on the internet.
Activists have protested against a number of companies involved in animal testing in recent years, targeting shareholders and businesses connected with laboratories.
As a result of intimidation and fears of bad publicity a number of smaller firms have moved out of the UK.
But Mr Garnier insited London-based GSK would not move its London headquarters elsewhere, despite the activities of a small group of extremists.
He added that it was "a pity" some firms had opted to quit the UK as their investment was critical to the country's new economy.
"This is what the UK needs more than anything else, more innovation - and a very tiny group of people is stopping good things from happening which would create meaningful jobs and would be one of those engines to the new economy that we so desperately need," he said.
"The UK needs more than Glaxo to prosper. This is where my concerns lie."
Instead he called on fellow drugs groups to "stand firm and not give up to blackmail" from anti-animal testing groups.
The government has pledged to look at ways to protect investor privacy following the events.
However Mr Garnier has said that he believes the current safeguards in the UK are sufficient.
"I think there are mechanisms to create anonymous shareholders," he said.
"Legislation is fine in the UK, what we need is more police action to ensure the legislation is acted upon."
The furore surrounding the threats to GSK investors prompted the Prime Minister to call for a greater focus on protecting "decent people" from animal rights campaigners.
In a speech to the Confederation of British Industry on Tuesday Tony Blair warned activists would "face the full force of the law".
Mr Blair has also signed a petition supporting the use of animals in medical research.
Meanwhile, recent events had also helped to prompt a shift in the public's attitude, despite animal rights activists "spreading false rumours" about the practice, Mr Garnier added.
"As the public become more educated about what's going on in medical testing, most people use their common sense that this is something that should be encouraged'" Mr Garnier said.
Mr Garnier made the comments before speaking at the firm's Annual General Meeting (AGM) on Wednesday.
It was announced at the AGM that Mr Garnier has extended his term as chief executive.
He had been due to step down in October 2007 when he turns 60, but will now stay on until May 2008.
GSK also said it aimed to boost its over-the-counter (OTC) medicines business, but declined to comment on whether it might bid for Pfizer's OTC unit.