Investigatory Powers Bill's 'Double Lock' protection system has an override

The proposed legislation will govern the surveillance powers of the police and intelligence agencies Credit: PA

The new Double Lock - having a senior minister and then a judge approve intercept warrants - is one of the toughest such regimes in the world says the Home Secretary.

But there is an override mechanism.

Senior Home Office sources today said that in urgent cases the warrant could be issued on the say so of the Minister alone. The judge would then have five days to approve it afterwards.

An urgent case could include a threat to life, or it could be that an operation might otherwise be compromised or a significant intelligence gathering opportunity lost.

Of the 2795 warrants issued last year, the Home Office sources say around 20 would have been considered urgent in this way.