Leading article: Young Russian - 1. British security services - 0

The Special Immigration Appeals Commission is hardly known as a hotbed of liberalism, which makes all the more damning its decision in favour of the MP's Russian research assistant, Katia Zatuliveter.

Upholding her appeal against deportation, the SIAC president said: "Nothing in the material which we have analysed suggests, let alone demonstrates, that the appellant exploited her relationships for the purposes of the Russian state."

Indeed, what emerged from the mostly secret hearings suggested some over-active imaginations at MI5, reinforced by residual Cold War stereotyping. Given the categorical nature of the decision, it is hard to fathom why the Home Office decided to defend the deportation order at tribunal.

The plus side is that the case could help banish the notion that every Russian abroad is likely to be a spy. But there is a negative side, too, in the doubts cast, again, on the competence of Britain's security services.