The prime minister has sought to play down the recent upsurge in attacks against coalition troops in Iraq.

Quizzed by journalists at his Downing Street press conference Tony Blair insisted that progress was being made.

"I am optimistic about the long term situation in Iraq," he said.

"Certainly the reports I get from the people that I talk to who come back from Iraq tell me that with all the security problems that are serious, nonetheless there is a considerable amount getting better."

But the prime minister accepted that the current situation was "very, very difficult".

"It is a tragedy that we have coalition forces and ordinary Iraqis being killed," he told journalists at his monthly press conference.

But he added: "We are actually making the country better, these people are trying to stop us."

Blair said the political timetable would see more power transferred to the people of Iraq.

"We don't want the occupation to go on a moment longer than it need, but on the other hand Iraqis don't want us to leave until the job is properly done."

However with recent attacks on American and other soldiers and civilians based in the country, he accepted that British forces were "deeply worried" about the present security threat.

Britain's envoy to Iraq earlier insisted Britain would stay on the ground "through to the end".

"This is a proud and brutal country, and we have taken on a big job, but we are going to finish it," Sir Jeremy Greenstock said.

"There is not a strategic military threat. There is no way in which we can be militarily defeated here.

"Obviously, we need the US and UK to support what we are doing through their governments and parliaments, and to some extent their public opinion."

But Sir Jeremy conceded that the coalition forces would encounter further difficulties over coming months.

"This is not a normal country. This is a highly dangerous enterprise to try and bring a traumatised country to democracy in the short space of 18 months or so," he said.

"We have been quite clear, the president and prime minister have been quite clear, we are seeing this through to the end.''