Confidential advice given to Gordon Brown relating to the Iraq Inquiry's remit must be published so people know why the Chilcot Report did not rule on the legality of the war, the SNP has said.

Former Scottish first minister Alex Salmond and SNP frontbencher Joanna Cherry both called on Philip Hammond to reconsider "refusing" to release the advice.

Their calls come after the long-awaited publication of the report into the 2003 Iraq War by Sir John Chilcot.

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The report strongly criticised the way former prime minister Tony Blair took the country to war on the basis of "flawed" intelligence and concluded that Saddam Hussein did not pose an "imminent threat".

However, while stating that the way the decision about the legal basis for the war was reached was "far from satisfactory", Sir John did not rule on the legality of military action.

As a result, ministers are now being urged to publish the advice given to then prime minister Gordon Brown in 2009 before he established the inquiry.

Raising the issue of legality during the first day of debate on the report in the House of Commons, Ms Cherry said: "The Government's refusing to release confidential advice Whitehall officials gave to Gordon Brown about the remit of the inquiry.

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"This advice was what made it impossible for Sir John Chilcot to rule on whether the 2003 war was illegal.

"The Government's refusal flies in the face of an information tribunal ruling which has ordered the material's release and it means the public cannot see what options were considered when deciding on the nature and the scope of the inquiry when it was established.

"Will the Government reconsider its refusal to release this information?"

But the Foreign Secretary insisted the issue raised by Ms Cherry was not the reason why Sir John had not ruled on the crucial issue of legality.

Mr Hammond said: "The Government in considering this report will look at all these matters but I have to say to you that that is not the reason that Sir John has primarily identified for his decision not to pass any view on whether military action was legal.

"He says that the inquiry is not constituted in a way, nor does it have the necessary skills or qualifications, to make that decision."

Ms Cherry intervened again and said: "This is not a criticism of Chilcot, it is a criticism of the present Government for refusing to release information about why the scope of the inquiry was restricted not to look at the legality - that's what the public want to know."

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Mr Hammond replied: "The point I'm making is that Sir John himself identifies the lack of qualification, not the lack of remit but the lack of qualification, of the members of the inquiry to reach that decision and says it could only be resolved by a properly constituted and internationally recognised court."

The Foreign Secretary also stressed that a "huge number" of documents had been released but "but clearly it is not possible to declassify every document".

Mr Salmond also weighed in and said: "Why won't the Government release the documents which might give the public and Parliament an insight into why the Chilcot Inquiry wasn't remitted and qualified to deal with the legality question?"

Mr Hammond again said Sir John had not identified a lack of remit for not ruling on the legality, instead identifying a "lack of appropriate skill sets in the inquiry".

The Foreign Secretary said the Government will examine the Chilcot Report in detail in the coming months and consider whether further documents should be declassified.

Shadow foreign secretary Emily Thornberry warned the mistakes made in the war in Iraq and highlighted in the Chilcot report are being repeated by the current Government.

She said MPs are still not being presented with the full facts on intelligence before being asked to back military action.

And she said the sectarian warfare that has erupted in Libya showed that Britain's reconstruction efforts are still woefully inadequate.

She singled out Government claims that 70,000 moderate fighters existed in Syria that could be joined up with to overthrow Assad for criticism.

Ms Thornberry said: "Many of us were sceptical about that 70,000 figure, I know I was certainly one of them.

"But the 70,000 figure was produced by the Joint Intelligence Committee and the Government declined to say which groups were included in that figure, where they were, what the definition of moderate was or how we could be sure that all these rebels were signed up to the coalition's military strategy, or indeed how they were going to get to the battlefield in order to be able to fight the battles.

"All of those questions mattered."

She said time will tell whether this estimate was correct, but she said: "But it does seem to me that there is a parallel to be drawn between the intelligence relied on in relation to the 70,000 figure, and flawed intelligence that has been relied on in the past.

"It seems to me that it is important, therefore, for us to learn the lesson from Iraq 12 years earlier.

"Serious questions have been raised about intelligence that underpins decisions that we make to take military action and in my view, once again, Parliament has simply been asked to take on trust what the Government says about intelligence."

Her remarks prompted head shaking by the Foreign Secretary Philip Hammond.

The biggest "tragedy" highlighted in the Chilcot report was the almost total lack of planning for reconstruction following the 2003 invasion, Ms Thornberry said.

She said: "If ever there was a mistake that should never be repeated, it is the idea that we are going into another military intervention with no idea of its consequences, no plan for the aftermath, and no long-term strategy.

"And yet, and yet, it is the exact hallmark of all the outgoing prime minister's interventions.

"Again we can see the evidence in Libya. The prime minster, in the words of President Obama, became 'distracted'.

"Once the Gaddafi regime had been overthrown and the lengthy, arduous task of post-war reconstruction was supposed to be started, it was all but ignored.

"And in the years since Libya has been riven with factionalism and violence, its experiment with democracy was brief, with the power in the hands of rival militias. And the ungoverned space that this created was an invitation to Daesh to establish a strategic foothold on the Libyan coast.

"It is a stain on this Government that it only began to pay any real attention to the mess it had left in Libya once that terrorist threat from Daesh became too urgent to ignore."

She latter added: "The central lesson is this; you cannot bomb a country from 30,000 ft into a Western-style democracy."

And she said the Attorney General must be confident enough to stand up to their PM when applying the rule of law.

She said: "Too often the outgoing prime minister has repeated exactly those same mistakes in his own military interventions, relying on speculative intelligence, keeping Parliament in the dark, and failing to plan for whatever happens afterwards.

"It is hoped the new prime minister will study the Chilcot report, not a commentary on decisions made in the past but as a guide to future decisions that she will have to make."

Tory former attorney general Dominic Grieve said the way in which evidence was handled in the run up to the decision to go to war was, in some cases, "truly breathtaking" and that the report made for "very troublesome reading".

Mr Grieve said his impression from reading the Chilcot report was that the attorney general at the time, Lord Goldsmith, was only provided with "sketch backgrounds" of the factual analysis on which his legal opinion was sought.

He said: "The big difference which I can tell the House without giving away state secrets is that if law officers are now being asked to advise on a factual basis which involves a serious or complex problem of international law they will receive briefing as good as and actually potentially better if they demand it than that which would be provided to the prime minister himself as to the intelligence and factual base that justifies it."

Mr Grieve said in 2003 and perhaps even before that "this was not the practice that was being adopted".

Mr Grieve later counselled caution on the possibility of starting contempt proceedings.

He said: "Just as some people were talking about impeachment, last used in 1806, contempt proceedings in Parliament, unless they are based on findings which have been made in an external tribunal which meets Article 6 compliance, is going to be in practice very difficult."

He said the "practical difficulties are likely to make it impossible to follow".