"Maybe what we decided at the beginning of the season doesn't function any more," team boss Toto Wolff told reporters at the Hungarian Grand Prix on Sunday. "We cannot really ask either driver to give up their position or jeopardise their own championship chances for the benefit of the team," added the Mercedes motorsport head.
Hamilton refused a request in the race to allow championship-leading team mate Rosberg, who had started on pole but was behind him on a different strategy and still had a pitstop to make, through.
The message 'don't hold him up' was made twice to Hamilton, who eventually finished third with Rosberg fourth, over the radio with a third of the race remaining. "I'm not letting him past me, if he gets close enough to overtake he can overtake," replied the 2008 champion, who stayed ahead for eight more laps until Rosberg pitted.
Had the Briton made way, Rosberg - who denied making any request to be let through - might have been able to win for Mercedes instead of both being beaten by Red Bull's Daniel Ricciardo. But Hamilton, who had started from the pitlane, would have fallen further behind in the championship instead of cutting the gap to 11 points with eight races remaining.
Hamilton said he was "very, very shocked" by the request.
"I was in the same race as him. Just because he had one more stop than me doesn't mean I wasn't in the same race as him," he explained. "And naturally if I'd have let him past, he would have had the opportunity to pull away and when he does pit, he's going to come back and overtake me. To be honest, he didn't get close enough to overtake but I was never going to lift off and lose ground to Fernando (Alonso) or Daniel to enable him to have a better race. So that was a bit strange."
Mercedes, dominant this season, have made a point of not imposing 'team orders' in an effort to keep the fans entertained but that has brought friction between their drivers as well as some thrilling wheel-to-wheel battles.
Wolff said in March that the pair were free to race, within defined limits and as long as the team did not lose out. He said on Sunday that with Mercedes now 174 points clear or Red Bull in the constructors' championship, and the drivers in a duel of their own for that title, there needed to be a fresh discussion of how to proceed. "It's a difficult situation now," he said. "The longer the season goes, the more intense it gets. At the beginning of the season it was easy to say these are the rules and this is how we are going to do it.
"Now it's clear these two are fighting for the world championship and it's more intense. We need to sit down and discuss it."
Mercedes have won nine of the 11 races to date - five for Hamilton - and Rosberg had been expected to celebrate his fifth on Sunday after starting from pole position with Hamilton last. Instead, the safety car threw the race on its head with Rosberg on a three stop to Hamilton's two.
Niki Lauda, the retired three-times world champion who is now non-executive chairman of Mercedes, said Hamilton did what he had to do. "I do understand that Lewis said 'Why? Why should I stop now in the middle of the circuit to let my team colleague by.' He is fighting for the championship," he told reporters.
"From my point of view, Lewis was right. Why the call came, this happened out of the panic and we had to make up for what we were losing. The call was unnecessary, afterwards, but it was made. Lewis ignored it and finished third, so looking backwards nothing wrong from my point of view," he said.
"It is important Lewis said 'No, I'm racing my team-mate anyway'. So he did the right thing."