OneWeb, a London-based satellite startup striving for global internet connectivity and a key competitor to Elon Musk's StarLink satellite internet constellation, was set to launch a batch of 36 internet satellites later this week as part of its plan for a 648-satellite constellation.

Those plans are now in jeopardy as Roscosmos, Russia's space agency, appears set to roadblock the effort.

A Russian-built Soyuz rocket operated by France's Arianespace SA was meant to deliver the satellites into low Earth orbit, launching from Russia-owned Baikonur Cosmodrome in Kazakhstan.

OneWeb and Russia inked a multi-year deal for satellite launches, with the company launching its satellites exclusively on Russia's Soyuz rocket.

But Dmitry Rogozin, Director General of Roscosmos and a former Deputy Prime Minister with a flair for inflammatory rhetoric, is refusing to go ahead with what should be a routine launch in response to UK sanctions on Russia following the invasion of Ukraine.

The agency is requiring that the UK government sell all stakes in OneWeb and that the company guarantees the satellites will not be used for military purposes, according to an ultimatum spelled out on Twitter from Roscosmos' official account.

Roscosmos stressed the demands are "due to the UK's hostile stance towards Russia".