British Prime Minister Tony Blair delayed his annual summer holiday on Friday to continue efforts to agree a U.N. Security Council resolution on a Lebanon ceasefire, his office said.

"Basically he's delayed to try and do further work to try and get this UN deal together. And he thinks the next few days will be critical," a spokesman said, adding that Blair would resume his holiday plans "within the next day or so".

Blair was due to fly to the Caribbean on Friday to join his family for a three-week break.

Recently, Blair's persistent refusal to listen to appeals from his cabinet ministers to seek an early ceasefire between Israel and Lebanon has led to growing criticism and dissent over his tough approach toward the Middl East conflict.

He has been under increasing pressure to postpone his holiday, scheduled to begin on Friday, until a ceasefire is agreed. But some critics have said his absence might be a blessing.

Speaking at his monthly press conference on Thursday, Blair hoped that there would be a UN resolution for an immediate ceasefire in Lebanon "in the next few days".

The U.N. Security Council resolution would pave the way for the deployment of an international force to help the Lebanese government control the southern area bordering Israel, he said.

It was "vital" to have a genuine ceasefire on both sides and to address the issues raised by Lebanon along with the Israeli requirement for security on its northern border, Blair said.

He believed the outstanding differences over the UN resolution could be quickly resolved. "This is obviously a critical time. I think it is coming together. I think the remaining differences are very slight," he said.