(Reuters) - Olympic long jump champion Greg Rutherford has branded the International Olympic Committee's decision not to impose a blanket ban on Russia at next month's Rio Games as "spineless" and expressed surprise that more athletes were not speaking out.

The IOC rejected calls for Russia to be banned from the Rio Games over its doping record on Sunday, putting the onus on international sports federations to decide whether individual athletes should be allowed to compete.

While the decision has been endorsed by some national Olympic committees, it drew criticism from athletes and the World Anti-Doping Agency (WADA), which said it would "inevitably lead to ... lesser protection for clean athletes."

"We know the pros and the cons of a blanket ban, we know the risks of 'collective justice', but we also know the risk of not punishing a culture of doping that comes from the very top," Rutherford told the Guardian.

"I would say that the latter is a much greater threat to sport. We've certainly not been given a clear message of transparency and progress. But no, what we have now is a messy, grey area that doesn't help anyone."

"This is a spineless attempt to appear as the nice guy to both sides."

The decision also received widespread criticism from other anti-doping bodies, with the USADA chief Travis Tygart and Australian sports minister Sussan Ley voicing their discontent.

The International Association of Athletics Federations (IAAF) banned Russian athletes from the Rio Games in November and Rutherford praised the sport's governing body's stance.

"I have to say I am proud of my own sport and its new leadership, for the proactive and strong stance taken a few weeks ago. Athletics set the right sentiment for a clean and believable sport," the 29-year-old said.

"... Without a consequence for institutional-level actions how on earth do we expect to make any progress?"

Rutherford also urged other high-profile athletes to follow suit and voice their opinion over the IOC's decision.

"I also feel a little surprised that more athletes are not more vocal about this, especially those with a powerful voice in Olympic sport," he said.

(Reporting by Shravanth Vijayakumar in Bengaluru; Editing by Peter Rutherford)