Donald Anderson said the PM was not in total support of Israeli policy
The prime minister has not endorsed US foreign policy as more than 50 former UK diplomats have suggested, according to the Labour chairman of the Commons Foreign Affairs Select Committee.
Donald Anderson MP, told BBC 2's Newsnight programme that Tony Blair did not support Israeli Prime Minister Ariel Sharon's plan to unilaterally disengage with the Palestinians as President George W Bush has done.
Newsnight's political correspondent Martha Kearney, has said that government sources have dismissed the ex-diplomats as the 'camel corps' - officials previously based in Arab countries who have gone native.
William Fullerton, who was UK ambassador to Kuwait from 1992-96, said on the programme: "In my mind we seem to be following America's interests tamely and the US neo-conservatives view of the Middle East is unrealistic."
Former UK ambassador to Libya Oliver Miles, one of the signatories, said the letter was prompted after the prime minister agreed with the president that Israeli settlements in the West Bank were now considered as acceptable.
"This is a departure from the principles on which any negotiated settlement is likely to be reached.
"One has not come away with the impression that there is a gap between the British and the Americans on these matters," he said.
Mr Anderson said that the diplomats' letter has not accurately reflected what the prime minister said on the Arab-Israeli conflict, following his Washington summit with the president.
"There was no endorsement of what the president called the realities on the ground or targeted killings, there was a greater emphasis on the United Nations.
"There has been no acceptance of the legality of the security fence built on the occupied territories.
"There was never any acceptance by the UK that borders and the right of return for Palestinians should be other than final status matters. So there was a real difference and I think the letter failed to note that," he told Newsnight.
But Mr Anderson said that with regards to Iraq, he did agree with part of the diplomats' letter such as the failure to predict what happened following the overthrow of Saddam Hussein and the use of inappropriate force in certain circumstances.