Rupert Murdoch's feud with Tony Blair reached new heights after an intimate note by Murdoch's ex wife Wendi has been exposed in a national newspaper - describing her 'warm feelings' for the former prime minister.

Speculation surrounding Blair's close friendship with Wendi Deng has been rife since the Mail on Sunday revealed their multiple encounters last week. This included overnight stays at two of Murdoch's homes in California without his knowledge - a fact which has not been disputed by either side, the newspaper claims.

Now the newspaper reports on a note written by Deng before the media tycoon filed for divorce when he discovered their meetings at his home. In it she describes in detail her warm feelings for Blair, which have been likened to a 'crush'.

Blair has always vehemently denied rumours of an affair with Deng and the Mail on Sunday has made it clear it has no evidence of an affair between them, which it said remained the case.

Several of Blair's close friends have challenged him on the matter and believe he is telling the truth.

One told the Mail on Sunday: "I believe Tony. He would never do such a thing and he is not a liar."

Another said: "Wendi was going through a very difficult time with Rupert and Tony was a shoulder to cry on. There is nothing more to it than that. Rupert is old and confused and has imagined all this."

A long-standing friend of Blair said: "Wendi was in a hateful marriage. Tony is a sympathetic guy and helped her through a bad time."

Friends of Murdoch insist it was not a light decision ending his 14-year marriage to Deng - the divorce was finalised last month - and his 20-year political and personal relationship with Blair.

A media executive who has known Murdoch for 40 years told the newspaper: "Rupert has supported Tony politically and personally through thick and thin, but he was wrong."

Another friend commented: "What really hurt was finding out that Tony had been in his homes without telling him."

The Mail on Sunday also revealed Blair was forced to stay away from the world's biggest media conference in the US in July. He was told by the organisers, Allen and Co, a New York based private investment bank, not to turn up when fellow guest Murdoch objected to his presence.

According to the newspaper, Murdoch told the bank he would stay away if Blair attended.

Blair was asked to withdraw and agreed but a source close to him claimed: "He cancelled all US engagements that week because of Middle East business."