Potential cross-examination of David Cameron about the refusal to order a public inquiry into the murder of Belfast solicitor Pat Finucane is being thwarted, the High Court has heard.


An affidavit from the Prime Minister’s private secretary blocks any chance of questioning him about claims he told the lawyer’s widow Geraldine that others around Downing Street would not allow a full independent probe, a judge was told.


Lawyers for Mrs Finucane are to seek an order striking out the “hearsay” statement that Mr Cameron denies making the comments.


It was also alleged that a sham consultation process was undertaken when the decision not to hold an inquiry had been pre-determined.


With papers in the case now to be served on the Irish Government, next month’s scheduled hearing of the challenge has been put back.


Mr Finucane was gunned down at his north Belfast home by the Loyalists in 1989.


His family have campaigned for a full independent inquiry and believed they were set to achieve that when they went to Downing Street to meet the Prime Minister last October.


Instead, they were shocked to be told that a review, conducted by a senior lawyer, rather than an inquiry would take place.


In an affidavit filed as part of their legal challenge, Mrs Finucane claimed the family was treated “cruelly”.


According to her, the only explanation for the apparent change of mind was the intervention of a person or persons unknown.


She alleged: “This view was supported by a comment made by the Prime Minister during the meeting when he said ‘It is true that the previous administration could not deliver a public inquiry and neither can we.


“There are people in buildings all around here who won’t let it happen’.”


It was revealed on Tuesday, however, that a senior official has averred that Mr Cameron instructed him that he did not use the words alleged.


Barry Macdonald QC, for the Finucanes, told the court his clients have a record of the meeting but no minutes have been made available from the British Government.


Because the affidavit was not by the Prime Minister himself, he cannot be questioned on its contents.


Mr Macdonald said: “We essentially will be suggesting this hearsay averment is a device to avoid the possibility of the Prime Minister being subjected to cross-examination on that issue.”


Mrs Finucane was in court as her barrister further contended that the decision not to hold a public inquiry was taken months before the October meeting.


“It’s going to be our suggestion that this consultation process was essentially a sham and the decision had been pre-determined.”


Paul McLaughlin, for the British Government, confirmed he would need to take instructions on the points raised.


The case, which was due to be heard in May, was listed for a further review in June.


Meanwhile, Sir Desmond De Silva’s review of the killing is continuing as he plans to report back by the end of the year.


Northern Ireland Secretary of State Owen Paterson has said he believes that the De Silva analysis is the best mechanism available to get to the truth of what happened in the case.