On Thursday, the SoftBank-backed satellite internet firm OneWeb—a rival to SpaceX’s Starlink operation—said in a terse statement that its board had “voted to suspend all launches from Baikonur.”

The company had been due to launch 36 satellites from the spaceport on a Soyuz rocket later this week, until Roscosmos, Russia’s counterpart to NASA, hit it with a last-minute ultimatum.

Roscosmos said Wednesday that the Soyuz-2.1b rocket—which was already installed on the launchpad—could not take off unless the British government were to divest its 45% stake in OneWeb, which it bought for $500 million a couple of years back as part of a rescue plan for the bankrupted company.

The Russian agency also demanded a guarantee that the satellites in the launch would not be used for military purposes.

“There’s no negotiation on OneWeb: The U.K. government is not selling its share,” responded British Business and Energy Secretary Kwasi Kwarteng.

Kwarteng tweeted Thursday that the British government supported OneWeb’s decision to suspend all Baikonur launches. “In light of Russia’s illegal and unprovoked invasion of Ukraine, we are reviewing our participation in all further projects involving Russian collaboration,” he added.

Neither OneWeb nor its launch partner—the French SpaceX competitor Arianespace—had at the time of publication responded to queries about whether they will continue to use their other facility of choice, the Vostochny cosmodrome in Russia’s far east.

The OneWeb episode comes a few days after the European Space Agency (ESA) said its upcoming Mars rover mission, a joint project with Russia, was “very unlikely” to go ahead this year as planned.

The ExoMars mission was due to take off from Baikonur in September, carrying a rover named after the scientist Rosalind Franklin. ESA blamed “sanctions and the wider context” for the delay.

After the Russian invasion drew heavy sanctions late last week—including high-tech sanctions that the U.S. explicitly said were designed to degrade Russia’s space program—the country retaliated by pulling Russian staff from Europe’s Guiana Space Center in French Guiana, a French overseas region on the northern edge of South America.

Europe is using the spaceport to build Galileo, its counterpart to the U.S. GPS navigation constellation: A Russian Soyuz rocket was supposed to add two new satellites to the Galileo constellation on April 6. However, European Commissioner Thierry Breton responded by saying Russia’s decision to withdraw did not threaten Galileo and Copernicus, the European Earth-observation satellite program.

As of Monday, the U.S. and Russia were still cooperating on the International Space Station—not that they have much choice, with four American astronauts and two Russian cosmonauts being up there currently. Russia runs the segment of the ISS that bears its rockets. As NASA has made clear, it would be financially difficult for the U.S. to in future maintain the ISS on its own.

However, Russia did last weekend kick the U.S. out of a project that aims to explore Venus—a planet that Russia rather bizarrely claimed as its own a year and a half ago. The gesture was largely symbolic as NASA’s involvement in the Venera-D project had been tentative in any case.

Roscosmos chief Dmitry Rogozin said Saturday that Russia would either execute Venera-D alone or bring in China.

He also said China could help Russia source the microelectronics it needs for its space program, that it can no longer get elsewhere under sanctions.

China and Russia already agreed in 2019 to codevelop an International Scientific Lunar Station to rival NASA’s planned Gateway lunar station, which Russia had previously been considering signing up to.

China has so far shown little appetite for joining international sanctions on Russia. Indeed, some of China’s biggest space contractors are themselves under U.S. sanctions for exporting missile technology.