Pannick’s second argument concerning parliament’s inability to scrutinise the government focuses on the relationship between parliament and the executive, and he described that ‘in constitutional terms, ministers are the junior partner. Parliament is the senior partner.’
A five-week prorogation therefore prevented parliament from not only legislating, but also that debates could take place and ministers could not be questioned. In his view, the ‘junior partner’ launched a ‘pre-emptive strike’ that ‘takes parliament out of the game’ for the whole period of prorogation.
He concluded this argument by saying that the sovereignty of parliament is the principle underlying the whole constitution, but the prime minister’s prorogation sought to undermine this sovereignty.
While these first two arguments are undoubtedly relevant and the motive of the prime minister may indicate his intentions, it is likely that the third argument will determine the outcome of this case. That is whether the case is even justiciable and can be heard by a court.
Unlike the Scottish Court of Session, which permitted the appeal, the English and Northern Ireland High Courts ruled that the case was not justiciable.
Once again, Pannick focused on the relationship between the executive and parliament, arguing that it was implicit in the power of the executive that it would not remove the power of scrutiny other than for a legitimate purpose.
While ending one session and starting another is a legitimate purpose, it is not lawful to prorogue parliament for so long as to frustrate scrutiny. He said in this case prorogation had the effect of ‘frustrating the constitutional principle of parliamentary sovereignty and supremacy over the executive’.
Pannick concluded his submission by saying that the case was justiciable for the reason that this was an unlawful exercise of a prerogative power by the prime minster and that the courts had the power to review prerogative powers such as prorogation which are not governed by statute.