Privacy campaigners have condemned Google for responding to British users' claims that it had illicitly tracked their web browsing by claiming that UK laws do not apply to it.

In a response to legal documents filed by a group of British users seeking to sue Google, the company said the case should be served in California, where it has its world headquarters, and refused to accept the lawsuit in Britain. It plans to contest the right of UK users to bring a case in the country where they live and use Google's services.

Google also dismissed the UK users' claims as "not serious", asserting that the browsing habits of internet users are not protected as "personal information", even where they relate to sexuality or physical health.

Nick Pickles, director of the pressure group Big Brother Watch, said: "It is deeply worrying for a company with millions of British users to be brazenly saying they do not regard themselves bound by UK law. Regulators need to step up and ensure that when citizens are illegally tracked against their wishes, the company riding roughshod over their privacy is held to account."

The lawsuit comes from a group of more than 100 British Apple users, called Safari Users Against Google's Secret Tracking, who have filed a damages claim that claims Google illegally violated their privacy in bypassing settings on Apple's iPhone and iPad browser to install tracking cookies without their permission.

The search giant paid a record $22.5m fine in the US in June 2012 after the US Federal Trade Commission investigated that use of tracking cookies against millions of American consumers. Google did not admit wrongdoing in the settlement.

Google confirmed in the FTC case that it had circumvented protection built in to the Safari web browser on the iPhone and iPad to track them using its DoubleClick advertising network without explicit consent. The circumvention was discovered in February 2012, but Google refused to say how long it had been carrying it out before then. A class action was filed in the US over the breach in February 2012.

Judith Vidal-Hall, a former magazine editor who is one of the claimants, said she was appalled: "Google's position on the law is the same as its position on tax: they will only play or pay on their home turf. What are they suggesting – that they will force Apple users whose privacy was violated to pay to travel to California to take action, when they offer a service in this country on a .co.uk site? This matches their attitude to consumer privacy. They don't respect it and they don't consider themselves to be answerable to our laws on it."

Marc Bradshaw, another claimant, complained: "It seems to us absurd to suggest that consumers can't bring a claim against a company which is operating in the UK and is even constructing a billion-pound headquarters in London. If consumers can't bring a civil claim against a company in a country where it operates, the only way of ensuring it behaves is by having a robust regulator."

Bradshaw said though that the UK regulator, the Information Commissioner's Office, had said it could only fine Google if it broke the law.

"Fines would be useless," Bradshaw said. "Even if Google agreed to pay them – because Google earns more than the [£500,000] maximum fine in less than two hours. With no restraint, Google is free to continue to invade our privacy whether we like it or not."

Lawyers for the claimants say that individual damages might be modest but that because millions of Britons use Apple devices and access Google services that in aggregate the sums could be significant.

Alexander Hanff, a privacy advocate who has been following the case, said: "I would hope that given the court already granted permission for the complaint to be served to Google Inc in California, that they will follow through and reject Google's defence." Writing on a website devoted to the case, he pointed to examples in Canada where Facebook had been sued in Canadian courts despite claiming its US status, and said that an FTC commissioner had "accepted that EU laws and EU countries do have extraterritorial jurisdiction with regards to enforcement of their laws".

Dan Tench, a partner at the lawyer's Olswang, which is acting for the claimants, told the Guardian: "there are important points of principle in this case. It's regrettable that Google are seeking to resist accountability for their actions. We hope that they will have the opportunity to be brought to account for them."

Google said it would not comment on ongoing legal actions.

The case is scheduled to come before an English court in October.

Google is already the target of concerted efforts by European privacy regulators, where France has given it a deadline of the end of September to change its privacy policies to meet local laws, while Spain is pursuing six counts of privacy infringement.

That followed Google's unilateral meshing together in March 2012 of privacy policies separately covering each of its services – such as Maps, search and YouTube – into a single one, effectively tracking a user's activity across all those services.

Antitrust regulators in Europe are also negotiating with the search giant to reduce what is seen as favouritism of its own products, such as Google Shopping, in search results above rivals.