Tony Blair overstated the threat posed by Saddam Hussein, sent ill-prepared troops into battle and had “wholly inadequate” plans for the aftermath, the UK’s Iraq War inquiry has said.

Chairman Sir John Chilcot said the 2003 invasion was not the “last resort” action presented to MPs and the public.

There was no “imminent threat” from Saddam – and the intelligence case was “not justified”, he said.

Mr Blair apologised but insisted that lives had not be lost “in vain”.

The report, which has taken seven years, is on the Iraq Inquiry website.

Prime Minister David Cameron, who voted for war in 2003, told MPs it was important to “really learn the lessons for the future” and to improve the workings of government and how it treats legal advice.

Labour leader Jeremy Corbyn – who voted against military action – said the report proved the Iraq War had been an “act of military aggression launched on a false pretext”, something he said which has “long been regarded as illegal by the overwhelming weight of international opinion”.

A spokesman for some of the families of the 179 British service personnel and civilians killed in Iraq between 2003 and 2009 said their loved ones had died “unnecessarily and without just cause and purpose”.

He said all options were being considered, including asking those responsible for the failures identified in the report to “answer for their actions in the courts if such process is found to be viable”.

Tony Blair responds to report

In a statement to the media, his voice at times cracking with emotion, the former Labour prime minister said: “I know there are those who can never forget or forgive me for having taken this decision and who think that I took it dishonestly.

“As the report makes clear, there were no lies, Parliament and Cabinet were not misled, there was no secret commitment to war, intelligence was not falsified and the decision was made in good faith.

“However, I accept that the report makes serious criticisms of the way decisions were taken and, again, I accept full responsibility for these points of criticism – even where I do not fully agree with them.”

He said the US would have gone to war in March 2003 “either with or us or without us” and the “stark decision” he faced on whether the UK should join them could not have been delayed.

“I did it because I thought it was right and because I thought the human cost of inaction, of leaving Saddam in power, would be greater for the world in the longer term,” he said.

He conceded that intelligence on Iraq’s weapons had “turned out to be wrong” and the invasion had destabilised Iraq but said he still believed the country was “better off” without Saddam Hussein.

He accepted Chilcot’s criticism that the UK had not sought sufficient assurances from the US about post-war planning but no one had “identified alternative approaches which would have guaranteed better success”.

The key points of the report

The report, which is 2.6 million words long, does not make a judgement on whether Mr Blair or individual ministers were in breach of international law.

But Sir John, the ex-civil servant who chaired the inquiry, does not pull his punches when criticising decisions made in the run up to war and in the aftermath.

He describes the Iraq War as an intervention that went “badly wrong” with consequences still being felt to this day.

He has harsh criticisms for UK military commanders, who the report says had made “over-optimistic assessments” of their capabilities which had led to “bad decisions”.

But in a statement at the launch of the report, he criticised the way the need for military action was presented to the public and MPs by Mr Blair and his ministers.

“The judgements about the severity of the threat posed by Iraq’s weapons of a mass destruction – WMD – were presented with a certainty that was not justified,” he said. “Despite explicit warnings, the consequences of the invasion were underestimated.”

UK military fatalities

Blair/Bush memos

Previously classified documents, including 31 personal memos from Tony Blair to then US president George W Bush, have been published alongside the Chilcot Report.

They show that momentum in Washington and London towards taking action against Saddam Hussein quickly began to build in the wake of the 9/11 attacks in 2001 in the US, which killed nearly 3,000 people.

The memos reveal that Mr Blair and Mr Bush were openly discussing toppling Saddam Hussein as early as December 2001, when the UK and US had just launched military action in Afghanistan.

“How we finish in Afghanistan is important to phase 2. If we leave it a better country, having supplied humanitarian aid and having given new hope to the people, we will not just have won militarily but morally; and the coalition will back us to do more elsewhere,” says Mr Blair in the memo.

“We shall give regime change a good name which will help in our arguments over Iraq.”

In January 2002, President Bush named Iraq as part of what he described as an “axis of evil” in what he said was a “war on terror” against al-Qaeda and other groups.

In another memo, from July 2002 – nearly a year before the invasion of Iraq – Mr Blair assured President Bush that the UK would be with him “whatever,” but adds that if Mr Bush wanted a wider military coalition he would have to get UN backing, make progress on Middle East peace and engineer a “shift” in public opinion in the US, UK and the Arab World.