Foreign Secretary William Hague said he would work with the people in authority in Egypt for the safety of British nationals, but said he "always" condemns military intervention in a democratic system. He told BBC Radio 4 Today's programme:
I always condemn military intervention in a democratic system. This is a military intervention in a democratic system. We have to understand it's a popular intervention, there's no doubt about that in the current state of opinion in Egypt.
So while warning about the precedent that it sets for the future, of course we have to work with the Egyptians, with the majority will in Egypt, and that's what we will do.
We will always be clear that we don't support military intervention but we will work with people in authority in Egypt. That is the practical reality of foreign policy.
The Muslim Brotherhood tells ITV News they are against violence but will "pay the price of their blood" to restore their ousted president.
Egypt's army has named two further officials in the transitional government as its supporters and opponents vowed to stay on the streets.
There has been outrage in Egypt after 51 people were killed near an barracks where ousted President Mohamed Morsi is thought to be held.