There is growing disquiet on the back benches of the ruling Conservative party that the PM is taking the nation down a path to a “hard Brexit” which would sever all ties between the EU and UK, see the UK leave the single market, European Court of Justice and, possibly, the European customs union. This is bad enough, but Mrs May has made her opinion clear that she can use a vestigial power from the days of rule by the monarch, the Royal Prerogative, to invoke Article 50 without the need to go to the Commons for a vote. This position is as contentious within parliament as it is outside and has led to claims that Mrs May is behaving like a “Tudor monarch”.
In a democracy, parliament passes bills which become law, but it up to the judiciary to determine if a law is being properly applied, so a challenge has been made to the High Court which seeks a ruling that the Royal Prerogative does not attach to invoking Article 50 – in other words, the government must seek the blessing of parliament first. Naturally, the government does not agree.
The argument turns on the fact that parliament has allowed the executive to deal with foreign policy under Royal Prerogative and that a decision to leave the EU is essentially foreign policy. The claimants argue that the referendum result seeks (inter alia) to strip British citizens of rights enjoyed as a consequence of EU membership (and subsequently ratified by the UK government) and that parliament alone has the right to remove or reduce rights granted under the law.
The government is claiming that: "The decision to withdraw from the EU is not justiciable. It is a matter of the highest policy reserved to the Crown.” They argue that authority was granted by parliament when it passed the 2015 Referendum Act and have argued that since it was passed with a ratio of 6:1, parliament has effectively washed its hands of the matter, but the referendum act makes it clear that the vote is not binding on government and therefore, this argument looks specious. A judicial decision is expected quickly and it is probable that the losing side will appeal the decision anyway.
Were a decision to be taken that determined that Article 50 can only be invoked with the blessing of parliament, it would not invalidate the referendum result as such. However, (with the exception of UKIP) the official position of all UK political parties was pro-remain and a large majority of MPs argued in favour of continued membership of the EU.
Unless Article 50 is properly invoked, the UK will remain a full member of the EU. One can understand why Mrs May wants to have the power to invoke the article herself, but as one major thread of the Leave campaign was the restoration of UK Parliamentary Sovereignty, one could legitimately suggest that this flies in the face of the very thing she claims to be serving (i.e. the will of the people).