Former minister for justice Alan Shatter has lost his challenge to the report by senior counsel Seán Guerin into his handling of claims by garda whistleblower Maurice McCabe.

Mr Shatter wanted to quash some of the findings of the report, published in May last year.

He resigned the day after the publication.

Mr Shatter claimed he had been given no opportunity to respond to criticisms and adverse conclusions made against him.

He claimed there had been an absence of fair procedures on the part of Mr Guerin.

Mr Shatter said Mr Guerin should have interviewed him before reaching conclusions on a range of issues.

But Mr Justice Seamus Noonan ruled that the nature of the exercise undertaken by Mr Guerin was in relation to Mr Shatter, limited to a consideration of the documents of the department for the purposes of advising the Government, of which Mr Shatter was a member, if further action was needed.

He said Mr Guerin was required to express a view and he did so.

The judge said the report was in the nature of an expert opinion from an independent senior counsel obtained by the Government on foot of a contractual arrangement privately entered into.

The judge said he could not see how Mr Shatter as a member of the Government that decided to obtain and publish the report could complain about the consequences.

Mr Justice Noonan also said the principle focus of these proceedings following their commencement was an attempt by Mr Shatter to stop the Commission of Investigation investigating his role in relation to Sgt McCabe's complaints.

That was now a fait accompli, he said, but he said Mr Shatter was still seeking to curtail the statutory investigation by undermining the conclusions on which he says it was based.

He said Mr Shatter was trying to mount a collateral attack on the commission. He said that could not be permitted.

Mr Justice Noonan dismissed Mr Shatter's claim on all grounds.

Mr Shatter later said he would reflect on the judgment.

The judge said it was clear from even a cursory perusal of the report that Mr Guerin's task was a mammoth undertaking to be completed in around eight weeks.

He said the time span given to Mr Guerin was a clear indication of the nature of the review required.

If Mr Guerin had to interview all the people identified as being involved in the events which Sergeant McCabe complained about, and give them the full range of fair procedures Mr Shatter said they should have received, then Mr Guerin's report could have taken months if not years.

He said Mr Guerin's report was intended as a preliminary exercise to assist the Government in determining if further steps should be taken.

He said Mr Shatter was suggesting Mr Guerin should have done what the Commission of Investigation is now doing.

The judge also found Mr Guerin's conclusions were not findings of fact or final determinations of anything.

He said they could not be challenged by way of judicial review.

The judge said Mr Shatter complained extensively about damage to his reputation and his career as a result of the report but singularly failed to explain why the conclusions were wrong.

He said Mr Shatter was given fair procedures entirely appropriate for the nature of the review Mr Guerin was carrying out.

The judge also strongly criticised the former justice minister in relation to a number of other issues.

He said that in correspondence with the Ceann Comhairle of the Dáil in late 2014 and early 2015, Mr Shatter's lawyers were making the case that including an examination of his role in the Commission of Investigation's terms of reference would be unlawful and unconstitutional and any attempt to do so would be challenged legally.

But the judge said Mr Shatter did not initiate such proceedings.

He said no mention of this was made in his submissions in this case.

The judge said this was an extraordinary change of position, entirely unexplained.

He said it was very difficult to resist the conclusion that these proceedings were initiated by Mr Shatter to stop his role in the investigation of Sgt McCabe's complaints being examined by the commission.

The judge said judicial review was a powerful weapon in the armoury of the court deployed to vindicate the constitutional rights of the citizen and protect them against unjust attack.

It did not, he said, exist to facilitate the adoption of strategies or tactical positions designed to achieve a different purpose and the court ought not permit its process to be used in this way.

Mr Shatter had originally accused Mr Guerin of objective bias.

He said Mr Guerin was a member of the Bar Council's Professional Practices Committee and he claimed that committee had publicly criticised the provisions of the Legal Services Bill and the approach taken in the bill to reforms which would affect the legal profession.

That committee did not make any such criticism of the bill.

Mr Justice Noonan said Mr Shatter had offered no apology or any expression of regret.

He said Mr Shatter withdrew the allegation four-and-a-half months after it had been made publicly and six weeks after it had been demonstrated to be entirely without foundation.

The judge said there was not the slightest attempt to explain how this very serious error was made by Mr Shatter.

The judge said this allegation was of the utmost gravity.

He said to have this allegation made very publicly by the former justice minister could hardly be more serious with all the implications it carried for Mr Guerin's professional reputation and future career.

The judge said Mr Shatter had a duty to find out the full facts before swearing on oath that those facts were true.

He said Mr Shatter's approach to this issue was entirely unacceptable.

The judge said it could not possibly be suggested by Mr Shatter that he was unaware his role in relation to Sgt McCabe's complaints was to be examined by Mr Guerin, having regard to statements Mr Shatter had made in Dáil Éireann.

He also said a claim by Mr Shatter that he bore no responsibility for correspondence addressed to his department but not specifically brought to his attention was extraordinary.