When in doubt, seek a mainland interpretation of the Basic Law. That seems to be standard for former justice chief Elsie Leung Oi-sie. We should be thankful she is no longer in charge of the city's legal department. Regrettably, she is a top adviser to Beijing on the Basic Law, hence all the talk among local deputies to the NPC about getting an interpretation to halt an influx of mainlanders seeking right of abode for their children by giving birth here. An interpretation by the Standing Committee of the National People's Congress should be considered 'the nuclear option' - considered only after all alternatives have been exhausted - and must be justified by an overwhelming public interest. We are not even close to such a dire state. That Leung already thinks an interpretation is justified says something about her cavalier attitude towards the rule of law. She said the government has the constitutional right to ask for such interpretations, so doing it cannot threaten the rule of law. Who is she kidding? There have already been four interpretations since the handover in 1997. The erosion of our legal independence is done slowly, never in one go, and each interpretation just weakens it more. Slowly, principle is sacrificed for expediency; seeking NPC interpretations becomes a de facto administrative measure, but camouflaged as a constitutional right. Even if we were to seek another interpretation, we don't need to do it now. A 1999 NPC interpretation could be cited to refuse granting permanent residency to babies of non-local parents. This could trigger a legal challenge going all the way to the Court of Final Appeal. It's only if the top court rules against the government that it would need to seek an interpretation. Secretary for Justice Wong Yan-lung said yesterday the decision to go to the NPC must be balanced by the need to protect the city's judicial independence. Fingers crossed he does not give in to political pressure.