It was supposed to be the final frontier, where the petty jealousies of earth and other planetary concerns were left behind. But space is not the haven of international harmony it used to be. Once upon a time, astronauts on the international space station shared resources - food, equipment, facilities. But now, a veteran Russian cosmonaut has complained that he is not even allowed to use his American colleagues' exercise bike - or his toilet.

According to Gennady Padalka, commercial squabbles on earth are starting to compromise morale in space. For seven glorious years after his first space mission in 1998, Padalka said he and his American astronauts had cooperated brilliantly. All this changed in 2005 when space missions were put on a commercial footing, he said, and Moscow started billing the US for sending its astronauts into orbit.

Padalka told Novaya Gazeta newspaper that officials had rejected his request to work out on the American exercise bike during their pre-training mission. Worse than that, they had also ruled that American and Russian crew members should use their own "national toilets", with Russian crew banned from using the luxurious American astro-loo.

"What is going on has an adverse effect on our work," Padalka, 50, was quoted as saying in an interview before he and his crew mates blasted off to the international space station last Thursday. They arrived safely on Saturday.

Padalka, who will be the station's next commander, said the arguments date back to 2003, when Russia started charging other space agencies for the resources used by their astronauts. Other partners in the space station responded in kind.

"Cosmonauts are above the ongoing squabble, no matter what officials decide," said Padalka. He went on: "We are grown-up, well-educated and good-mannered people and can use our own brains to create normal relationship.

"It's politicians and bureaucrats who can't reach agreement, not us, cosmonauts and astronauts."

The standoff over the gym machine appears to mirror the dismal relationship between Moscow and Washington under the former US president George Bush and Russia's Vladimir Putin.

He said he had inquired before the mission whether he could use an American machine to stay fit.

"They told me: 'Yes, you can'. Then they said 'no'. Then they hold consultations and they approve it again. And now, right before the flight, it turns out again that the answer is negative."

While sharing food in the past helped the crew feel like a team, the new rules oblige Russian cosmonauts and US and other astronauts to eat their own food, Padalka said, conceding that the US astronauts generally had tastier stuff.