Boris Johnson has called for demonstrations to take place outside Russia's embassy over Moscow's involvement in the Syrian conflict.
The Foreign Secretary warned that the "wells of outrage are growing exhausted" as MPs expressed their horror at the human suffering caused by the bombing of the city of Aleppo.
He said the Government would consider calls from numerous MPs to look at setting up a no-fly zone in the region but insisted the UK could only commit to it if it was willing to shoot down offending aircraft.
Mr Johnson said: "It is the UK week after week that is taking the lead together with our allies in America and in France, all the like-minded nations, in highlighting what is happening in Syria to a world where, I'm afraid, the wells of outrage are growing exhausted."
He added: "There is no commensurate horror, it seems to me, amongst some of those anti-war protest groups.
"I'd certainly like to see demonstrations outside the Russian embassy.
"Where is the Stop The War Coalition at the moment? Where are they?"
MPs claimed during an emergency Commons debate that Russia is responsible for committing war crimes in Syria as they called for Britain to review its relationship with President Vladimir Putin's regime.
Former cabinet minister Andrew Mitchell opened the debate having already compared Russia's attacks on Aleppo to the Nazi regime's bombing of Guernica during the Spanish civil war.
He said: "The effects of the crisis in Syria on our children and our grandchildren will be every bit as great as the effects of Brexit."
He also pressed Mr Johnson to meet with former prime minister Sir John Major to discuss how he helped impose a no-fly zone in northern Iraq in the 1990s.
Mr Johnson said he was willing to talk to "everybody involved in the 1991 effort".
Conservative Tom Tugendhat (Tonbridge and Malling), who served in the British Army, was one of many MPs who called for the introduction of a no-fly zone.
"Militarily there is no reason we could not enforce a no-fly zone that is affecting so many people," he said.
Tory Bob Stewart, a former United Nations commander in Bosnia, added: "I've operated under a no-fly zone. It is practicable. It can work."
Mr Johnson said the Government "must work through all these types of options" but warned: "We cannot do that unless we are prepared to shoot down planes or helicopters that violate that zone and we need to think very carefully about the consequences."
Shadow foreign secretary Emily Thornberry described the situation in Aleppo as "truly a hell on earth" with civilians "trapped" and "desperately in need of food, clean water and medical care".
"It is a scale of suffering beyond our comprehension," she said.
She stressed the importance of the UK working with Russia to re-establish a ceasefire as she also criticised the Government for continuing to sell arms to Saudi Arabia which stands accused of breaching international humanitarian law in the war in Yemen.
She said: "We cannot cry for the people of Aleppo and the suffering that they face while turning a blind eye to the million children in Yemen facing starvation today."
Meanwhile, Conservative former minister Jonathan Djanogly suggested the UK should reconsider its relationship with Russia.
"On the one hand we see the Russians dropping bunker bombs on hospitals, but on the other hand we're allowing them to come and trade in our country as though nothing is going on," he said.
"Does this not need a general review of our relationship with Russia?"
Labour's Ann Clwyd, who served as special envoy on human rights in Iraq from 2003 until 2010, called for protests to take place outside Russian embassies across the world "until the bombing campaign stops".
There were also calls for evidence to be secured now for potential war crimes prosecutions and for the UK to track all Russian and Assad regime aircraft operating in the region.
Mr Johnson suggested Russia's current course of action risked turning the country into an international outcast.
He said: "If Russia continues in its current path then I believe that great country is in danger of becoming a pariah nation and if President Putin's strategy is to restore the greatness and the glory of Russia then I believe he risks seeing his ambition turn to ashes in the face of international contempt for what is happening in Syria."