Prime Minister Gordon Brown today insisted the Government had taken all precautions necessary to guard against a swine flu pandemic, saying he had "absolutely no doubt" there would be more cases in Britain.
The premier was speaking after the World Health Organisation raised its alert level over the virus to phase five of six.
Mr Brown said: "I do understand British people will be concerned about this development. They will want to know what it means for the health and safety of the British people.
"I do want to reassure the British people that we are taking all the precautions that are necessary. We have been prepared for a scenario such as this for many years."
Mr Brown, asked about the flu crisis at a press conference in No 10 following a meeting with Iraqi premier Nouri Maliki, went on: "I understand that the number of cases is growing in many countries.
"I also understand that the cases that have been detected and confirmed in Britain are all from people who have come back from Mexico. These cases so far have been mild cases and the people who have suffered have responded to treatment.
"I have absolutely no doubt there will be more cases. We have the supplies in place and are ready to respond to the needs of the British people."
The Prime Minister said the latest situation was discussed at this morning's meeting of the Cabinet.
"We discussed what I think the country is most worried about at the moment: how we can prevent the escalation of swine flu, how we can take all the precautions that are necessary, make sure we have the orders for the supplies we need."