The office said the Syrian National Coalition was "emerging as a credible alternative" to the regime of President Bashar Assad, The Daily Telegraph reported Tuesday.
The recognition came as the Syrian Network for Human Rights reported 101 deaths Tuesday, including six children. SNHR reported 43 deaths in Damascus and its environs, 18 in Aleppo, 12 in Lattakia, eight in Idlib, six in Raqqa, five each in Hasakee and Homs, three in Deir al-Zor and one in Daraa.
The coalition, formally called the Syrian National Coalition for Opposition and Revolutionary Forces, was formed this month in Doha, Qatar, to unite Syria's fractured opposition groups to try to enhance their chances of securing foreign aid and arms in their fight against Assad.
British Foreign Secretary William Hague told Parliament the decision was reached after he met the coalition's leaders last week and was convinced they are committed to human rights and responsible leadership. He said he had asked the group to appoint a political representative to Britain.
Hague previously said he had pressed coalition leader Ahmed Moaz al-Khatib and his two aides on the need to include all Syria's minorities and to respect human rights.
With reports indicating at least 100 people die every day in Syria, Hague said his government would not exclude the possibility of providing military support for the rebels later. He announced London will send more than $1 million in aid for communications equipment and infrastructure, as well as other forms of non-weapons aid.
"We will not rule out any option in accordance with international law that might save innocent lives," Hague said.
The European Union's 27 foreign ministers Monday officially recognized the new anti-Assad coalition as a legitimate representative of the Syrian people. Full diplomatic recognition, however, will be up to each EU member state individually. France and Italy also have recognized the rebel coalition.
Iran's supreme Ayatollah Ali Khamenei Monday criticized foreign governments for arming Syrian rebels and said if the opposition forces lay down their arms it would be possible for them to hold talks with the Assad regime, the FARS News Agency reported.
"If the opposition forces in Syria give up their weapons, then the government can be demanded to listen to the opposition views and allow them to express their views," Khamenei said during a meeting with Iranian Hajj officials in Tehran.
Khamenei said the Syrian crisis cannot be settled as long as outsiders supply rebels with weapons, the report said.