A decision by the main, western-backed Syrian opposition group to attend peace talks aimed at ending the country's bloody civil war was welcomed by the Foreign Secretary.
William Hague said the Syrian National Coalition's decision should be supported by all who wanted a "democratic and pluralist" future for the country.
The coalition was under huge pressure from its Western and Arab sponsors to attend the peace talks, scheduled to open on Wednesday in Montreux, Switzerland.
Of the 73 voters who made the decision at a meeting in Istanbul, 58 were in favour of attending the so-called Geneva II peace conference.
It will be the first face-to-face meeting between the representatives of president Bashar Assad's regime and the opposition since the country's crisis began in March 2011, killing more than 100,000 people and displacing millions.
Mr Hague said: " I welcome the decision by the National Coalition to participate in the Geneva II talks. All who share their vision of a democratic and pluralist Syria need to join together in support.
"The National Coalition reached this difficult decision against the backdrop of continued brutal regime attacks on Syrian civilians, and the deliberate blocking of humanitarian aid.
"The UN Secretary General has made clear that the aim of the talks is to agree a political transition and an end to the conflict. In contrast to the National Coalition, the Syrian regime has still not agreed to this aim. As I have said many times, any mutually agreed settlement means that Assad can play no role in Syria's future."
Mr Hague and Prime Minister David Cameron have come under pressure from charities to open the door to vulnerable Syrians fleeing the conflict.
Organisations including Oxfam, Save the Children and Amnesty International criticised the British Government for keeping the UK's border under "lock and key".
The 25 charities signed a letter insisting that ministers needed to change their policy and accept Syrians in response to a call from the United Nations High Commissioner for Refugees (UNHCR).
The letter, co-ordinated by the Refugee Council, said: " People in neighbouring states have shown incredible compassion and opened their homes to hundreds of thousands of people but we all have a shared responsibility.
"It would be catastrophic if the neighbouring countries closed their borders to the thousands of people who flee the conflict every day. Yet how can we call on Syria's neighbours to keep their borders open to refugees if we keep our own under lock and key?"
The UNHCR has appealed to Western governments to accept 30,000 of the most vulnerable refugees trapped in the region.
So far 18 countries including Germany, France and the USA have signed up but the UNHCR is still over 10,000 places away from meeting its target.
Shadow home secretary Yvette Cooper said it was "immoral" not to respond to the UNHCR call.
She said: "Western European countries are only being asked to help some hundreds of the most vulnerable refugees - and to help those who have family connections in Europe who can help and support them too.
"France, Germany, Austria, Finland, Holland, Ireland and others have all agreed to do their bit.
"People will feel ashamed that our government is one of the only ones to refuse to help. It is immoral to stand aside when countries as far afield as Canada and Australia are willing to help."