Was the government’s recent extradition review one-sided? The highly experienced extradition solicitor Karen Todner complained in last week’s Gazette that the Scott Baker inquiry did not interview a single defence practitioner.

It is certainly surprising that Sir Scott Baker and his two colleagues - one of them a defence lawyer and the other a prosecutor - did not take oral evidence from anyone at the sharp end, although they must have received a very clear message when they spoke to Liberty, Justice and Fair Trials International.

That said, any defence lawyer or defendant was welcome to submit written evidence to the review team - and some did. One of the points that the law firm Kingsley Napley made was that the so-called forum bar should be implemented. A similar view was no doubt expressed in the written evidence submitted by David Bermingham, one of the ‘NatWest Three’ bankers who pleaded guilty to wire fraud after being extradited to the US in 2006.

And that is the topic I want to explore here. I did not mention the forum bar in my article of 27 October - to which both Todner and Bermingham responded - because I had discussed it in a column published here on 30 June. But it is worth re-examining in the light of the Scott Baker recommendations.

The forum bar is a provision in the Police and Justice Act 2006 that would allow a judge to refuse extradition where ‘a significant part of the conduct alleged to constitute the extradition offence’ took place in the UK and ‘it would not be in the interests of justice for the person to be tried for the offence in the requesting territory’.

Although passed by parliament, this provision originated in a Conservative amendment and has never been brought into force - despite a change of government. Scott Baker takes the view that implementing it now would be a backward step.

The review team points out that, whenever a suspect raised the issue of forum, the judge would have to investigate whether a prosecution in the UK was viable and, if so, whether there were good reasons for not bringing one. The court would have to consider the evidence available in both the requesting state and in the UK. That would be costly and time-consuming.

Nor would it have made any difference in any of the cases heard so far. Take the NatWest Three, for example. As Scott Baker notes, both the district judge and the High Court found that the case had very substantial connections with the US and was perfectly properly triable there. Similarly, the English courts agreed that the US would be the place to try Todner’s client Gary McKinnon, the man with Asperger syndrome who admitted hacking into US military computers from his home in London a decade ago.

So what are the arguments in favour of a forum bar? Most of them boil down to saying that a UK judge is better placed than a foreign prosecutor to decide where someone should stand trial, especially if the requested person is given the opportunity to be heard in open court. Scott Baker also detected a hint of chauvinism: the argument that British citizens should be tried by British courts.

That last claim is unlikely to get very far. Although some countries refuse to extradite their own nationals, it is a diminishing number. Who wants the extra expense of prosecuting and punishing people in your own country when others are willing and eager to do it for you?

The main argument against a forum bar is that it would impede the extradition process and undermine international co-operation. It would generate satellite litigation, brought on behalf of potential defendants who preferred to be prosecuted in the UK. They, in turn, would demand wide-ranging disclosure of evidence. The detailed investigation required by the 2006 legislation would have a detrimental impact without any corresponding advantage.

Michael Caplan QC, a partner at Kingsley Napley, acknowledges that the specialist district judges who gave evidence to Scott Baker could not think of a single case that should have been tried here in the interests of justice.

‘Introducing the forum bar now may be just a sop to please campaigners,’ Caplan admits. ‘On the other hand, in the next case that comes along we may find legitimate and compelling reasons for the court to consider a forum bar, if available. I believe it should be introduced for this reason.’ That is a an entirely proper argument for a defence lawyer to take. But it is, I have to say, only one side of the story. What motivates the inquiry team is a belief that if the UK becomes less willing to hand suspects to other countries, they will be less willing to extradite people to the UK.

Fortunately, Scott Baker had a little-noticed trick up his sleeve. He recommended that prosecutors in the UK should publish guidelines setting out the significance to be given to residence and nationality when deciding whether a suspect should be prosecuted or extradited. If a prosecutor failed to give sufficient weight to the suspect’s right to family life when choosing where the trial should take place, this could be challenged by judicial review.

This is a much more promising means of redress for suspects such as McKinnon. As the attorney general indicated in the Commons last week, it is a reform the home secretary will now have to consider. Since Theresa May clearly has no wish to extradite McKinnon, she may well regard it as a lifeline.