Charles Clarke, the Home Secretary, and Jack Straw, the Foreign Secretary, have both begun their summer breaks and Tony Blair is about to take his holiday. In their absence, John Prescott, the Deputy Prime Minister, will head the Government, while Hazel Blears, the Home Office minister, will deputise for Mr Clarke.
The decision to allow three of the most senior cabinet members to leave the country at the same time was strongly defended yesterday by Geoff Hoon, the Leader of the Commons.
He told BBC News 24 Sunday: "It is necessary for ministers to take a break. Charles Clarke in particular has had a very tough time in recent weeks.
"It is important that he is able to spend time with his family, with his children, and then come back refreshed to be able to deal with the continuing threat to the country. But can I emphasise there are very senior ministers in London day-to- day taking responsibility for whatever may arise."
But Geraldine Smith, the Labour MP for Morecambe and Lunesdale, said: "There is an argument that they have to go on holiday at some time, but at this moment in time it's a bit insensitive. Perhaps the holidays should have been postponed for a couple of weeks." Hywel Williams, the Plaid Cymru MP for Caernarfon, said: "It does seem a bit strange they are away on holiday - they should be here in case we have another incident. If Parliament is recalled, the appropriate ministers need to be there very quickly."
Mr Clarke delayed his holiday for two days to attend a Downing Street meeting on the terrorism threat before joining his family in the United States. Details of the holiday destinations of Mr Blair and Mr Straw are being kept secret for security reasons. Sky News attracted the wrath of Downing Street last week by disclosing where the Blair family are vacationing.
The Government has stressed all senior ministers are regularly in touch with London and can swiftly return in a crisis. It has said it is prepared to recall MPs, who have just begun their 80-day summer recess, in an emergency.
The expectation is growing that Parliament could be brought back briefly next month to update MPs on the threat to Britain and preparations for fresh anti-terrorism legislation.
A report that David Blunkett, the Secretary of State for Work and Pensions, would take charge of his former department in Mr Clarke's absence was strongly denied by the Home Office. A spokesman said there was no role for Mr Blunkett and that Mr Clarke would be kept informed of any major developments.