British Prime Minister Tony Blair will delay the start of his holiday to work on a U.N. deal for a cease-fire in Lebanon, his office says. "Basically he's delayed to try and do further work to try and get this U.N. deal together. And he thinks the next few days will be critical," a spokesman said, adding he expected Blair to delay his departure by several days. Blair said on Thursday he was "hopeful" that the United Nations Security Council would agree a resolution implementing a cease-fire in the Middle East within the next few days. Speaking at his monthly Downing Street press conference, Blair said Western powers are working "very hard" to develop an agreement on a U.N. Security Council resolution that would bring about "an immediate cease-fire" and then establish conditions to deploy an international force in Lebanon. "This is obviously a critical time. I think it is coming together. I think the remaining differences are very slight" Blair was quoted as saying by CNN. "The U.S., the UK, France and others have been working very hard to get agreement on a United Nations resolution and I am now hopeful that we will have such a resolution down very shortly and agreed within the next few days.