Those due to be evacuated were called by phone and asked to gather at a meeting point where Lebanese officials would check their passports.
They were then taken by bus to the ship for a 10-hour journey to Cyprus. Journalists were asked not to identify the meeting point because the embassy was worried that large numbers of people ineligible for the evacuation might start gathering there.
After landing in Cyprus, Britons will be expected to make their own arrangements for travel to Britain or elsewhere at their own expense, but consular officials will be on hand to provide advice.
Unlike the US, the British government is not charging its citizens for the evacuation. Americans in Beirut are complaining that they have been asked to sign forms agreeing in advance to pay unspecified sums to cover the cost of their evacuation. Some said they had been told they would not be allowed to use their passports again until they paid.