Given that, in the majority of cases in extradition proceedings defendants sought to rely on ECHR, art 8, the Court gave guidance on (i) the approach that should be taken at the extradition hearing by a district judge and (ii) the proper approach on an appeal.
Before the district judge, the Court noted 6 factors that needed to be taken into account. Firstly, the cases of Norris v Government of the United States of America (No 2)  UKSC 9 and HH v Deputy Prosecutor of the Italian Republic, Genoa  UKSC 25 set out the principles to be applied when ECHR, art 8 was raised in the context of resisting extradition. Further HH v Deputy Prosecutor of the Italian Republic, Genoa had to be read in the context that it involved children.
Second, the public interest in ensuring that extradition arrangements were honoured was very high. So too was the public interest in discouraging persons seeing the United Kingdom as a state willing to accept fugitives from justice.
Third, the decisions of the judicial authority of a member state having made a request should be accorded a proper degree of mutual confidence and respect.
Fourth, decisions on whether to prosecute an offender in England and Wales were, on constitutional principles, ordinarily matters for the independent decision of the prosecutor. Challenges to those decisions were generally only permissible in the pre-trial criminal proceedings or the trial itself.
Fifth, factors that mitigated the gravity of the offence or culpability would ordinarily be matters that the court in the requesting state would take into account.
Sixth, in relation to conviction appeals, the judge at the extradition hearing would seldom have had the detailed knowledge of the proceedings, of the background or previous offending history of the offender which the sentencing judge had had before him. Each member state was entitled to set its own sentencing regime and levels of sentence. Provided it was in accordance with the Convention, it was not for a UK judge to second guess that policy.
The Court then considered the role of the appellate Court on appeal from the district judge. The Court held that the single question for the appellate Court was whether or not the district judge had made the wrong decision. It was only if the court concluded that the decision had been wrong, applying Re B (a Child)  UKSC 33, that the appeal could be allowed. Findings of fact, especially if evidence had been heard, ordinarily had to be respected.
Applying the above principles, the Court held that it was proportionate to extradite Adam Celinski. Celinski was subject to 3 warrants, and had 2 separate hearing before a district judge. At his first hearing the district judge discharged 2 of those warrants, but at the second hearing the district judge ordered his extradition on the third. The Court held that Celinski ought to be extradited on all 3 warrants, and noted that the first district judge had “substituted his own view of how the Polish court should deal with Celinski. His view was clearly wrong. He should have recognised that the decision on the punishment of Celinski was for the Polish court. The important public interests in upholding extradition arrangements, and in preventing the UK being a safe haven for a fugitive as Celinski was found to be, would require very strong counter-balancing factors before extradition could be disproportionate.”
In all the other appeals the Court found in favour of the requesting state, and either quashed the decision discharging the warrant (and remitting the matter for reconsideration) or gave its approval to the extradition. In one case, however, the Court sought clarification as to whether extradition ought to proceed as the defendant had served the length of this sentence while on remand in a UK prison.
Julian B. Knowles QC and Hugh Southey QC were involved in this case.