Tony Blair and George Bush were caught in an unguarded moment yesterday when they discussed the Middle East conflict without apparently realising that their words were being picked up by a live microphone.

In the conversation, at the G8 summit in St Petersburg, the two leaders appeared to be discussing moves to put pressure on Syria to halt attacks on Israel by the Lebanese militant group Hezbollah.

Mr Bush told the Prime Minister that the key to solving the current hostilities is to "get Syria to get Hezbollah to stop doing this shit".

And Mr Blair appears to offer to make a personal visit to the region in order to prepare the way for US Secretary of State Condoleezza Rice.

The Prime Minister warns of the danger of the situation in the Middle East going into a "spiral". And he suggests that he would be able to talk to key players in order to ensure that any peace-making visit by Dr Rice is a success.

At one point, the President appears to express frustration with UN Secretary General Kofi Annan, saying he felt like telling him to get onto the phone with Syrian President Bashar Assad and "make something happen".

Access to the conversation was abruptly halted after Mr Blair queried whether the microphone was "open".

Mr Blair's official spokesman later declined to comment on the conversation.

A transcript provided by Sky News reads:

Bush: Yo, Blair. How are you doing?

Blair: I'm just...

Bush: You're leaving?

Blair: No, no, no not yet. On this trade thingy...(inaudible)

Bush: Yeah, I told that to the man.

Blair: Are you planning to say that here or not?

Bush: If you want me to.

Blair: Well, it's just that if the discussion arises...

Bush: I just want some movement.

Blair: Yeah.

Bush: Yesterday we didn't see much movement.

Blair: No, no, it may be that it's not, it may be that it's impossible.

Bush: I am prepared to say it.

Blair: But it's just I think what we need to be an opposition...

Bush: Who is introducing the trade?

Blair: Angela (Merkel, the German Chancellor).

Bush: Tell her to call 'em.

Blair: Yes.

Bush: Tell her to put him on, them on the spot. Thanks for (inaudible) it's awfully thoughtful of you.

Blair: It's a pleasure.

Bush: I know you picked it out yourself.

Blair: Oh, absolutely, in fact (inaudible).

Bush: What about Kofi? (inaudible) His attitude to ceasefire and everything else... happens.

Blair: Yeah, no I think the (inaudible) is really difficult. We can't stop this unless you get this international business agreed.

Bush: Yeah.

Blair: I don't know what you guys have talked about, but as I say I am perfectly happy to try and see what the lie of the land is, but you need that done quickly because otherwise it will spiral.

Bush: I think Condi is going to go pretty soon.

Blair: But that's, that's, that's all that matters. But if you... you see it will take some time to get that together.

Bush: Yeah, yeah.

Blair: But at least it gives people...

Bush: It's a process, I agree. I told her your offer to...

Blair: Well...it's only if I mean... you know. If she's got a..., or if she needs the ground prepared as it were... Because obviously if she goes out, she's got to succeed, if it were, whereas I can go out and just talk.

Bush: You see, the ... thing is what they need to do is to get Syria, to get Hezbollah to stop doing this shit and it's over.

Blair: Syria.

Bush: Why?

Blair: Because I think this is all part of the same thing.

Bush: Yeah.

Blair: What does he think? He thinks if Lebanon turns out fine, if we get a solution in Israel and Palestine, Iraq goes in the right way...

Bush: Yeah, yeah, he is sweet.

Blair: He is honey. And that's what the whole thing is about. It's the same with Iraq.

Bush: I felt like telling Kofi to call, to get on the phone to Assad and make something happen.

Blair: Yeah.

Bush: We are not blaming the Lebanese Government.

Blair: Is this...? (at this point Blair taps the micro-phone in front of him and the sound is cut.)