The Lords constitution committee has published a report saying the royal prerogative should no longer be used as the legal basis for sending UK troops into actions. According to the reports it should be Parliament that votes on such things. Whilst this sounds fine, won't such a change mean there is a fundamental constitutional shift in the allegiance of the Armed Forces?
As I understand it, members of the Armed Forces take an Oath of Allegiance to the Crown, not Parliament. If Parliament has formal power over the deployment of the Armed Forces what does that mean for their Oath of Allegiance? I don't wish to sound alarmist, but what happens if Parliament votes to implement Martial Law? What safeguard would exist to stop that? As it stands, the Crown and the Royal Prerogative (which remains the Monarch's and not the Prime Minister's in actuality) is what protects against that sort of thing happening.
If we do scrap the Royal Prerogative and replace it with a vote in Parliament there must be necessary protection from abuses of powers, and there will need to be changes to the Oath of Allegiance I would've thought.
Edit: In the comments Dynamite has kindly pointed out that we won the English Civil War and so the monarch is only a theoretical impediment to tyranny, and by implication doesn't matter anyway. Ones belief in the value of the Monarch's roles I think comes down to personal opinion and on that I disagree. The way the system works at the moment you have one PM and one Monarch. If the Monarch wanted to act, it would be, for want of a better term, one against one. However, in the case of a Parliament it would be many against one and so Parliament would claim legitimacy even if it was like a loaded Reichstag. As I said in the last paragraph, we need safeguards if we remove the prerogative.