Microsoft has hit back at the UK after its acquisition of Activision Blizzard was blocked, saying the decision was "wrong" and would "shake confidence in the UK tech industry."
The Competition and Markets Authority (CMA) ruled on Wednesday that the deal would give Microsoft too much power in the video game market, and could lead to higher prices and less choice for consumers.
Microsoft has vowed to appeal the decision, and has said it believes the deal is in the best interests of both consumers and the UK economy.
In a statement, Microsoft president Brad Smith said: "Today's decision is wrong for the UK, wrong for gamers, and wrong for competition. It will stifle innovation, reduce choice, and raise prices.
"We have a long history of investing in the UK, and we are committed to continuing to do so. But today's decision will shake confidence in the UK tech industry and make it more difficult for other companies to invest in the UK."
The CMA's decision is a major setback for Microsoft, which had been hoping to close the deal by the end of July.
The deal is still subject to review by regulators in the US, Europe, and other countries.
It is unclear how the CMA's decision will affect those reviews.
However, the decision is a sign of the growing scrutiny that tech giants are facing from regulators around the world.
In recent years, regulators have been increasingly concerned about the power of tech giants, and the potential for them to use their market power to harm consumers.
The CMA's decision is a reminder that tech giants are not immune to government regulation, and that they will need to be careful about how they use their power.