Publishers have filed a lawsuit against Google to recover $4.2 billion ($3.4 billion) in lost revenue.

Charles Arthur, a former technology editor for the Guardian, claims that Google illegally limited the amount of money publishers could make from internet advertisements by abusing its dominant position in the market.

Google declared that it will vehemently oppose the "speculative and opportunistic" action.

Following the filing of a related lawsuit in November, this is the second instance of its kind.

Claudio Pollack, a former director of Ofcom, filed the lawsuit and is suing the Internet giant for up to £13.6 billion in damages.

The cases concern advertising technology - adtech - that decides in a fraction of a second which online adverts consumers will see, how much they will cost, and how much publishers will earn.

Online display advertising is the main source of income for many websites.

The UK competition regulator, the Competition and Markets Authority (CMA), is also investigating Google's dominance in advertising technology.

In the lawsuit, which was filed on Thursday, Mr Arthur claims that because of Google's abuse of its position, the prices of adtech services were inflated, and ad sales revenues of publishers were unlawfully reduced.

"The CMA is currently investigating Google's anti-competitive conduct in adtech, but they don't have the power to make Google compensate those who have lost out. We can only right that wrong through the courts, which is why I am bringing this claim," he wrote.

On Tuesday, Google asked a court to dismiss the case - arguing that the US government had overstated its hold on the market.

In 2021 the French competition regulator, Autorité de la concurrence, fined Google €220m for favouring its own services in the online advertising sector.