British Prime Minister on Sunday admitted mistakes in the run-up to the US-led war against Iraq, but refused to bow calls for a full apology.

"The intelligence that we had that he had actual deployable weapons has turned out to be wrong...Some of the information that we acted upon was wrong," Blair said in an interview with the BBC.

"The fact is, I think what some people want me to do is say sorry for getting rid of (former Iraqi President) Saddam (Hussein) and that I can not say because I do not believe that," Blair argued.

Blair, the staunchest US ally on Iraq, still insisted that to withdraw troops from Iraq would be to "surrender" to terrorists and denied there had been poor planning for the post-war situation in Iraq.

However, he said the degree to which terrorists from outside the country had moved in had surprised everybody.

Blair's comments came amid fears for Briton Ken Bigley, held hostage in Iraq by militants who have demanded the release of all women held in the US-run jails in the country.

The abduction of Bigley by militants who have killed Bigley's two American colleagues, in addition to the ongoing violence in Iraq and the lack of evidence of Iraq's weapons of mass destruction, has put new pressure on Blair.

Two new polls have suggested public support for Blair's ruling Labor Party draining away, with one survey putting the party in third place for the first time in more than 20 years.