The Government has argued that too much time has passed to allow a fair trial over alleged atrocities by British authorities in Kenya in the 1950s.
Guy Mansfield QC said the Foreign and Commonwealth Office faced "irredeemable difficulties" with witnesses and documents to defend the claim.
Without those witnesses, and indeed with the necessarily limited recollections of those who do survive, the very complicated and difficult task of determining the competing factual positions cannot be fairly conducted.
There is a dearth of evidence which can be given as to what was in people's minds when they made decisions and sent or read telegrams or attended meetings or were told of matters or visited places.
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Former Chancellor Lord Geoffrey Howe was Margaret Thatcher's longest-serving Cabinet minister, also taking on the role of Foreign Secretary.
Lord Geoffrey Howe is known by many for his resignation speech which was seen as the catalyst which destroyed Margaret Thatcher.