Britain has protested to Egypt against the nationalisation of the Suez Canal Company. A Foreign Office spokesman said in London that a copy of the strong British protest note despatched on July 27 to Cairo was also handed over to the Egyptian Ambassador to Britain, Mr. Samy Abdul Fetouh. In the House of Commons, the British Prime Minister, Sir Anthony Eden, hinted, in reply to a question, that consideration was being given to the possibility of blocking Egypt's sterling balances - funds held in London - but he stressed that no decision had yet been taken. The British note, protesting against the "arbitrary action which constitutes a serious threat to the freedom of navigation on a waterway of vital international importance," says that the responsibility for the consequences of President Nasser's action in announcing the nationalisation of the company must rest with the Egyptian Government. A message from Cairo said Egypt had rejected the protest notes of Britain and France.