Senior Tories have backed Russia's planned military intervention in Syria saying working with Bashar Assad is the "lesser evil" in the fight against Islamic State.
The Russian parliament voted unanimously to allow action in the country after a request for assistance from Mr Assad.
Bob Stewart, a member of parliament's defence select committee, welcomed the decision despite Russia's support of the Assad regime, stating "in order to defeat the great Satan you might have to put up with a lesser devil as well".
The Conservative MP for Beckenham said: "I am pleased that the Russians have said they are going to intervene and I hope very much that it helps contribute to the extinguishing of this appalling threat to mankind."
Mr Stewart described Islamic State (IS), also known as Daesh, as "the most foul enemy that we face".
"This is the classic doctrine of the lesser evil," he said.
"Assad is a lesser evil than Daesh.
"Personally as a member of parliament I think Daesh is the most foul enemy that we face and just like in the Second World War, combining with the Russians would not be a bad thing - but in the end Assad has got to be mitigated at the very least.
"I am moving toward the position, and have been for a while, that it may be that we will have to put up with Assad because of the doctrine of the lesser evil but it is still a pretty nasty regime."
Mr Stewart said he is "not totally against" the idea of accepting Assad for the moment, but "in the end the Syrian regime has to be brought to book in one way or another, probably by its own people".
Meanwhile, James Gray, the Conservative MP for North Wiltshire and fellow defence select committee member, also welcomed the decision of the Russian parliament.
He said: "My enemy's enemy is my friend, to some degree.
"You can't fight both Assad and IS at the same time."
The Russian vote came after President Vladimir Putin met with US president Barack Obama at the United Nations to discuss the situation in Syria.
Moscow has said it will not be sending ground troops to Syria but will use its air force to target IS.