The primary concern here is that there should be a clear distinction between the legislature (Parliament) and the executive (Government).
Should the executive thus be separated, the obvious and logical outcome is that the prime minister and his ministerial team would no longer be Members of Parliament. Prime ministers would have to be elected in their own right, a process which would reflect the increasingly presidential nature of general election contests.
Direct election would correct a manifest unfairness in our current arrangements exemplified by Prime Minister David Cameron who gained office by virtue of 33,973 votes in the 2010 general election. All those votes were cast in the constituency of Witney, which boasted 78,220 electors. The rest of the nation was not allowed to vote for the man. He may have been elected as an MP, but he was not elected as prime minister through a general franchise.
By contrast, it is ironic then to see the noted commentator, Conservative MEP Daniel Hannan elsewhere complain about â€œthe disturbing contempt for democracy at the heart of the EUâ€, because of its unelected commissioners and the commission president, when less than 0.2 percent of the 46 million-strong electorate in this country are allowed to vote for their prime minister.
Furthermore, when Mr Cameron holds office on the back of 10,703,654 Conservative votes, from an electorate of 45,844,691, his franchise represents only 36 percent of the votes cast and less than a quarter (23 percent) of the overall electorate, Mr Hannan is in no position to complain about lack of democracy in the EU â€“ if our own elections are taken as the measure.
As to why the general issue of â€œseparation of powersâ€ is so important to us, a useful port of call is the Wikipedia entry. It tells us that this need first emerged in ancient Greece. The state was divided into branches, each with separate and independent powers and areas of responsibility so that no branch had more power than the other branches. The normal division of branches is the executive, legislature, and judiciary.
Here, the defect in the British system is immediately evident, stemming from our transition from rule by an absolute monarch, to a system of constitutional monarchy. The executive that emerged to challenge the power of the king now comprises the prime minister and cabinet. But, in holding the power previously held by the king, it has effectively become the king. Thus, as long as Parliament is the body from which the executive is drawn, and as long as members of the executive are also Members of Parliament, there will be imperfect separation between the two bodies.
In practical terms, members of the ministerial team (including the prime minister) - the core of the executive - are appointed either from MPs in the House of Commons, from the Lords, or - not uncommonly - are appointed to the Lords for the purpose of making them ministers.
The use of the Commons as the recruitment pool for most of the ministers (and the prime minister) has a highly corrosive effect on the institution. Although the main functions of parliament should be scrutiny of the executive, and as a check on its power, all MPs who have ministerial or secretarial positions hold dual roles as members of the executive and the legislature. Inevitably, there is a conflict of interest.
Typically, there are around 140 ministers, whips and other office-holders in the Commons. Collectively, they are known as the â€œpayroll voteâ€, people who may be assumed to vote with the government, and to defend it policies and actions. But the problem is far worse than this basic arithmetic would suggest. Add the Parliamentary Private Secretaries (PPS) and the â€œgreasy pole climbersâ€ who have hopes of preferment but have not yet been promoted, and the number climbs to 200 or so on the government benches. When it comes to holding the government to account, all these people are compromised.
Even then, this is by no means the full extent of the distortion. The fact that the Commons is the main pool for recruiting ministers - and the only prime ministerial pool â€“ also changes the dynamics of the institution. A goodly number of people who enter parliament have no intention of remaining MPs for their entire careers. They want to join the government. For them, parliament is not an end in itself, but a means to a different end, the first step on a career path which ends up in ministerial office. This should not be the case.
We thus concede the obvious: ministers and other office holders cannot be members of parliament. If members become ministers, they must resign as MPs. As a consequence, prime ministers must appoint their own ministers â€“ from whatever source they choose â€“ subject to parliamentary confirmation and dismissal. This has the added advantage of widening the recruitment pool.
Mention here must be made of the Monarch, who remains head of state, with roles and duties unchanged. Furthermore, the office of prime minister keeps the title. The fact that a prime minister is elected does not, per se, turn the office into a presidential post.
There are then other details we need to establish. One is the period of office and the number of times an individual can stand. Arguably, the US system of four years per term and a maximum of two terms is a good model. But the detail is not important at this stage, even if it could become so later. Sufficient at the moment is the principle â€“ that we should have elected prime ministers. They and their ministers must be separate from Parliament and held to account by it.