David Cameron discussed the crisis in Egypt with US president Barack Obama on Saturday evening as a flight carrying Britons fleeing the stricken country touched down in the UK.
The Foreign Office chartered-flight arrived at Gatwick Airport at around 9pm with around 70 passengers on board who were kept away from other flight arrivals as they were escorted through the airport building by officials.
Tourists caught up in Egypt's chaos and British passport holders living in the troubled country made up the majority of those on board. An FCO spokeswoman said 76 people were on board - including a number of embassy staff.
Egypt lurched into further chaos on Saturday amid reports that the top leadership body of the country's ruling party, including the president's son Gamal Mubarak, had resigned.
Protesters have shrugged off other concessions offered by the regime in the past 12 days of unprecedented street demonstrations, saying they will settle for nothing less than the immediate removal of President Hosni Mubarak, Egypt's ruler for nearly 30 years. Tens of thousands of people gathered again on Saturday in Tahrir square, waving flags and chanting a day after some 100,000 massed there in an intensified demonstration labelled "the day of departure," in hopes it would be the day Mubarak left office.
Mr Cameron and Mr Obama spoke on the telephone to reaffirm their desire for the transition to a "broad-based" government to begin immediately. A Downing St spokesman said: "They agreed that it was vital that the Egyptian government respond to the aspirations of the Egyptian people through reform not repression. Violence was unacceptable. The Prime Minister welcomed the restraint shown by the army in policing the most recent protests.
"The leaders agreed that it was for the Egyptian people to determine the leadership of their country. But they were clear that an orderly transition to a broad-based government, with real, visible and meaningful change needed to start now.
"The Prime Minister said that a clear and credible roadmap to change was needed as soon as possible, including a path to free and fair elections. They agreed to keep in close touch in the coming days."
The latest blow came as 82-year-old President Mubarak continued to resist calls for his immediate resignation. He has said he will serve out the remaining seven months of his term to ensure a stable process.
He has warned that chaos would ensue if he were to leave now and said he told president Obama: "You don't understand the Egyptian culture and what would happen if I step down now."