The decision to block the extradition of Gary McKinnon is set to pave the way for a 'forum bar' which would give judges the power to bar prosecution overseas if they believe it is in the interests of justice.

During yesterday's (16 October) announcement of the decision in the high-profile McKinnon case, Home Secretary Theresa May confirmed plans to introduce the forum bar, which would mean – in cases where prosecution is possible in both the UK and another state – UK citizens could present their defences in the UK rather than facing extradition.

White & Case white collar partner Alistair Graham was among the original proponents of a forum bar in 2006, when it received backing from the then Shadow Attorney General Dominic Grieve and MP Nick Clegg.

"This provision will provide judges with more discretion in deciding whether it's in the interests of justice for cases to be tried in the UK – basically, it will allow UK courts to deal with UK issues," Graham said.

Graham led a White & Case team representing former Morgan Crucible CEO Ian Norris on his lengthy – and ultimately unsuccessful – battle from 2003 to 2010 against extradition to the US on charges of price-fixing and obstructing justice.

Corker Binning partner Andrew Smith added that the forum bar was long overdue, and that it should "increase public confidence and understanding about jurisdictional decision-making in cross-border investigations".

However, he cautioned: "Ultimately we'll have to see how it is drafted, but it's difficult to see how this will generate anything other than delay in extradition cases, which is exactly what the Lord Chief Justice recently spoke out against."

Smith pointed to a review of extradition laws by Sir Scott Baker which found that judges "could not think of a single case already decided under the Extradition Act 2003 in which it would have been in the interests of justice for it to be tried in the UK rather than the requesting state".

Hickman and Rose criminal defence partner Tom Epps added: "I see it as a positive development, both in the introduction of a forum bar and the forthcoming publication of the draft prosecutors' guidance for cases involving concurrent jurisdiction.

"To have more clarity as to which authority will take the lead in multijurisdictional investigations makes sense both for those who are the subject of possible extradition proceedings and the UK authorities."

"The proposed changes are significant when one considers that corporate crime investigations frequently involve concurrent jurisdictional issues."

The proposed extradition of British computer hacker Gary McKinnon to the US was blocked yesterday after a long-running battle, with Home Secretary May saying that such as move would be "incompatible" with his human rights.