Brentford-based drugs giant GlaxoSmithKline has been accused of denying UK tax coffers a fair proportion of its profits by listing lucrative brands in foreign countries.
GSK has been named in a Guardian newspaper investigation as an example of a UK-based company listing intellectual property - which generates profits on royalties and trademarks - in tax-friendly countries to get around the full force of the UK's 28 per cent rate of corporation tax on UK profits.
The firm, which employs 18,000 people in Britain and has the Brentford base listed as its global headquarters, faces questions on why it uses branches of the company in countries like Puerto Rico - which have lower tax rates - to list its more profitable assets such as big brands of drugs.
Twickenham MP and Liberal Democrat shadow chancellor Vince Cable backed the newspapers' campaign to shed light on the way big business protects profits from the UK tax system, writing: "Companies should pay the government of their host country for the infrastructure and other tax-financed services they receive: education, health, transport systems, policing."
However, GSK is also listed in America where around 50 per cent of its operations are carried out and claims to only conduct around five per cent of its business in Britain.
A GSK spokesman said: "Given that we are a global company with over 100,000 workers employed all over the world in many different countries we feel it's perfectly appropriate to list our intellectual property in different places.
"We feel it is the nature of global business and routine to do that.
"What I would whole-heartedly deny is that it is some kind of tax avoidance. We meet all the UK standards which are detailed in our annual report and I would emphasis that we do pay the corporate tax rates."
He added that GSK also contributes taxes through employees' PAYE.
It has been reported that the group would announce 6,000 to 10,000 job losses, but a Glaxo spokesperson refused to confirm or deny the rumours, only saying the company is implementing an ongoing restructuring programme and are due to announce their fourth-quarter results today.