No 10 unease at Brown's contacts with John Kerry

John Kerry, the frontrunner to challenge George Bush for the US presidency this autumn, has held a series of private meetings with Gordon Brown. The Senator set to win the Democratic nomination has links with the Chancellor stretching back over a decade.

Mr Kerry once even offered to send a private plane to ferry the Chancellor to a meeting with him in the US, The Independent on Sunday has learnt. Friends of Mr Brown last night admitted that the close relationship between the pair was likely to discomfort Downing Street.

"Having a British cabinet minister close to the main challenger to a US President is potentially a bit embarrassing," said one.

Tony Blair last week said that he had "learned enough... not to interfere in the American presidential election".

Nevertheless, Mr Blair is bound to become embroiled in the re-election effort of his ally in the Iraq war during a planned visit to Washington later this year.

Meanwhile, Brown supporters are quietly offering help and advice to the campaign team of the man seeking to unseat Mr Bush.

The Massachusetts Senator first came to the attention of Mr Brown, then Shadow Chancellor, in 1992 when he wrote a scathing report on the BCCI banking scandal.

The Chancellor's allies say there was "traffic" between the two politicians on the affair as Mr Brown sought to maximise its political damage to John Major.

Mr Brown, a frequent holiday visitor to the state represented by Mr Kerry, was later introduced to him by mutual friends in the Democratic Party. The Chancellor turned down his offer of a plane-ride but later met Mr Bush's main challenger in Washington, according to an ally of Mr Brown. The pair met again in London when they dined together with Senator Ted Kennedy, who is another close friend of Mr Brown.