Defence secretary Geoff Hoon has conceded that there are "different and passionately held" views on Iraq.

Addressing the Labour Party conference, the beleaguered minister said the government had not taken the decision to go to war on a whim.

He paid tribute to the 51 British servicemen and women killed since the conflict began but insisted they were there to "help build a better Iraq".

"I do want to emphasise that no-one takes a decision to use military force lightly," said Hoon.

"Whether and when to intervene militarily is always the most difficult decision to take."

Hoon, who is widely tipped to resign once the Hutton inquiry reports, said he had "spoken to bereaved family members too often lately".

The government was absolutely committed to "help rebuild the country", said Hoon.

And "whatever our sincerely held differences", the party should now unite in its determination to restore order inside the country.

Hoon insisted that British troops would not become "unsung heroes" along with the logistics experts, territorial army drivers and theatre nurses now engaged in rebuilding Iraq.

British troops were now "demonstrating their excellence at peacekeeping and their skill in a demanding and sensitive task of reconstruction", but the defence secretary admitted that "legitimate concerns remain" about security and Iraqi infrastructure.

In a speech in which the Cabinet minister avoided any references to his own political troubles, Hoon said there was "renewed pride" in Labour's internationalist tradition.

He said Labour was now "contributing to peace, a force for good, upholding our values at home and around the world".