The Pakistan’s People’s Party (PPP) led government in Sindh has a complicated history with law enforcement. Even right now it is tussling with the Centre over the powers given to the Rangers to patrol Karachi and is at odds with its own appointees to high positions in the Sindh Police. However the decision made to expel the National Accountability Bureau (NAB) – the federal anti-corruption and accountability body – from the province is the most bizarre, and the problematic conflict yet.

The Sindh government plans to end the application of the National Accountability Ordinance (NAO) 1999 by repealing it, and replacing it with their own “anti-corruption department”. Before we talk about the illegality of the move – and that is a forgone conclusion as it is – the reasons given by the Sindh government deserve a look.

Chief Minister Murad Ali Shah gives two; the NAB has failed to end corruption in the province and it exclusively target’s PPP members. While the first part of the statement is undoubted true – the Sindh government remains corrupt – perhaps some part of the blame – some would argue all – rests on the corrupt officials, who at this moment belong to the PPP. The second reason is more indicative of the true motivations; PPP needs to escape the pressure put on it by law enforcement agencies. But these NAB investigations are not all unsubstantiated witch hunts, as early as last month the body struck plea bargains with several Singh government officials; which means they accepted their wrongdoings and pledged to return funds the appropriated.

However, since the Sindh cabinet is unanimous in following this path, criticising faulty premises will not make much difference; if the bill is tabled in the provincial legislature, the PPP majority will see it through.

What comes next is more interesting. NAB, like NADRA and FIA is a federal agency. It was established by federal law and is administered from the Centre. As such there is no conceivable way in which a province can unilaterally change or repeal the application of a federal body’s laws in its territory. This fact is not some convention or general principle – it is a central tenet of the constitution. It is not some obscure, fine point that is open to interpretation either – it is an unequivocal rule that is present in almost all constitutions that follow the provincial model. The province has right to legislate in matters entrusted to it, but even there if there is conflict the federal laws take precedence.

The law here is settled, and the Sindh government knows it; they must be aware that their effort will never succeed.