Domestic Afghan politics were behind President Hamid Karzai's veto of Paddy Ashdown as the new United Nations envoy there, the senior British diplomat said on Sunday.
Ashdown said Kabul's objections to his candidacy - and Karzai's recent criticisms of British and US military tactics - were "almost certainly" to do with internal Afghan politics.
"President Karzai, a man whom I respect and I wish him well and I wish his government well, is a politician," the former British political party leader and international envoy to Bosnia-Herzegovina, told BBC television.
"He's lining up, hopefully, as he would see it, to win the presidential elections likely to be in 2009. I suppose he must have calculated that beating up on Britain - an ex-imperial power - beating up on the United States, was not going to do him any harm in a proud Afghanistan amongst the [ethnic] Pashtun vote."
Ashdown said he had not wanted the job when he was first approached by US Secretary of State Condoleezza Rice in October and made it clear the role needed the active support of the Afghan government.
It was not about having the power he had in Bosnia because Afghanistan is a sovereign state, but instead concerned co-ordinating the international community, he said.
He said he had spoken to Karzai and understood the conditions were in place, until he fell out of favour.
According to a Financial Times report on February 4, Karzai and his government's fury at a secret British plan to train former Taliban militants was behind the expulsion of two senior UN and EU diplomats late last year.
The Afghan leader has also said the security situation had worsened in the volatile southern province of Helmand, despite the efforts of the 7,800 British troops who are mainly based there, prompting criticism in London.
Ashdown told the BBC that the British ambassador to Kabul had told him that "Britain is being used to get at you", prompting him to withdraw his candidacy for the post in the wider interest of bringing security to Afghanistan.
Describing Afghanistan as a "failed state", he said it was more important now to work out how to defeat the militants and most importantly, keep public opinion there on side or else face a long, more difficult task.
The former British military officer said: "I remember in Belfast in 1969 when I was a young soldier, we were welcomed by the Catholics with cups of tea and sandwiches.
"It took us a year to lose their support and 35 years to gain it back again." (AFP)
Ashdown blames Afghan politics for UN envoy veto