The log cabins of Camp David in the Catoctin Mountains of Maryland will tomorrow once more be the setting for the awkward mating ritual between an American president and a British Prime Minister.

It was at the same spot, more than six long years ago, that Tony Blair first met President Bush and then — as now — the White House told Downing Street it wanted the meeting to be informal.

The Prime Minister, after some intense consultation with his style advisers, wore a pair of blue corduroys later described by the man who was British ambassador at the time as “ball-crushingly tight”. Mr Bush made a strange joke about sharing the same toothpaste — Colgate — and a ring of confidence formed around their relationship.

Tomorrow, when Gordon Brown’s helicopter lands at Camp David, Mr Bush will greet a Prime Minister who does not really do leisure wear and lacks the easy-going charm of his predecessor.

The British contingent have received dress code advice to be as “casual as you are comfortable with” at the president’s weekend retreat. Asked how Mr Brown would be interpreting this, an official replied: “I suppose the PM could always take his tie off. He wants it to be businesslike, Gordon is a businesslike guy.”

Aides say they hope that photo-opportunities will be limited to Monday’s press conference. Is Mr Brown packing his own toothpaste? “Probably,” replied a No 10 source.

Such inhibitions matter in Washington, where Mr Bush sets great store by looking into the eyes of world leaders before deciding if he trusts them.

And, while the Prime Minister does not wish to damage relations with a man who has another 18 months left in the White House, he also has good reason to avoid too public an embrace with someone loathed in by the British public and whose war in Iraq did much damage to Mr Blair.

The two have met before when Mr Brown was still Chancellor earlier this year, for a carefully organised “impromptu drop-by” in the office of Stephen Hadley, the president’s National Security Adviser.

Gordon Johndroe, Mr Hadley’s spokesman, said that the meeting was “warm and constructive — there was certainly no need for an interpreter”.

But, asked for a specific instance of their rapport, he replied: “It’s hard to describe. We should reserve judgment until after this weekend when they have had a chance to speak freely with each other.”

Mr Bush and Mr Brown will have a one-to-one dinner on Sunday night. On Monday morning they will have a private breakfast, before more formal talks where they will be joined by the likes of Mr Hadley and Condoleezza Rice, the Secretary of State.

David Miliband, the Foreign Secretary, will also arrive at Camp David on Monday where he may not wish to be reminded about a party at the American embassy in London on the night of the last presidential elections in 2004 when he turned up sporting a provocatively large “Kerry/Edwards” badge on his lapel.

Although this can be dismissed as youthful enthusiasm on his part (he was only a junior minister at the time) Washington nonetheless senses a change in tone.

It has been noticed, for instance, that Mr Brown will draw the political sting of his visit to Camp David by flying to New York on Tuesday where he will meet Ban Ki-Moon, the United Nations Secretary-General.

There has also been some irritation at the appointment of Lord Malloch-Brown, a trenchant critic of the president during his own time at the UN, to a post in the Foreign Office where he has already declared that Britain should no longer be “joined at the hip” with America.

Mr Brown and Mr Miliband have been at pains to emphasise that the US remains “Britain’s most important bilateral relationship”. And in recent weeks this has been expressed without the overly elaborate qualification - initially attached to it by the Foreign Secretary - that relations with Europe are not bilateral because Britian is part of the EU.

But even yesterday, a new book by the Labour-leaning IPPR think tank called for a rethink on relations with America, because “importance does not always mean agreement”.

Aides expect plenty of agreement on Monday. Britain will push for the revival of an international trade deal this autumn. Nor do officials expect to hear either Mr Brown or Mr Bush say “anything startlingly new” on Iran or Iraq. British officials do not believe recent reports that Mr Cheney is persuading the president to bomb Iran, while on Iraq they are content to wait for September’s report on the progress of the surge.

Reports this week that Mr Bush might be considering abandoning his opposition to binding caps on carbon emissions appear to be premature.

Times Recommends

• Zardari still has to tackle tough questions
• Material evidence 'debunks' Turin Shroud
• BBC criticised over Uganda gay execution poll