Can someone who's not MP...

[MASHED POTATOES. VOTE!]

Right, that's British not U.S.-related topic, but...

My question is as follows: can technically someone, who's neither a member of Commons and Lords, become the Prime Minister?

[Lincoln Republican]

My answer to your question would be no.

Great Britain has a parliamentary system of government.  The Prime Minister is the leader of either the majority party in the House of Commons, thereby having the confidence of the House, or, as in the current parliament, the leader of the party that, through coalition, has gained the confidence of the House.

Party leaders in the United Kingdom are chosen by their particular party caucus members.

The outgoing Prime Minister advises the monarch as to who should become the next Prime Minsiter.  The monarch has one governmental advisor, in this respect, and that is the Prime Minister.  The leader of the main opposition party or any other party does not go to the monarch to advise the monarch that they have the confidence of the House.  The monarch would then call upon the individual named by the outgoing Prime Minsiter and ask if he or she has the confidence of the House of Commons.  If they do have the confidence of the House, the monarch then calls upon that person to form a government. 

In theory, though not in practicality, yes, parliamentary members of a party in Great Britain can elect a party leader from outside the parliamentary membership.  If, in the unlikely event this did occur, the new leader would have to gain a seat in the House of Commons as soon as possible, through a byelection.  In the meantime, until that individual gains a seat in the House, the parliamentary caucus would be led by whoever the parliamentary caucus chooses to lead them until the new leader has a seat in the House.  If this leader not in the House was the leader of the governing party, they would not be sworn in as Prime Minister until after they have gained a seat in the House, and until they have been called upon by the monarch and asked if they have the confidence of the House.  The House member leading the party in the Commons would serve as Prime Minister until the new leader of the party gains a seat in the Commons.

The Prime Minister is answerable to the House, therefore, the Prime Minister must be a member of the House.

[MASHED POTATOES. VOTE!]

The Prime Minister is answerable to the House, therefore, the Prime Minister must be a member of the House.

Right, which was the reason Douglas Home resigned his peerage to gain a seat in by-election, so he could be member of commons.

However, strictly technically, would a non-House PM allowed?

[J. J.]

The Prime Minister is answerable to the House, therefore, the Prime Minister must be a member of the House.

Right, which was the reason Douglas Home resigned his peerage to gain a seat in by-election, so he could be member of commons.

However, strictly technically, would a non-House PM allowed?

Home, IIRC, was PM for a few weeks prior to winning a by-election.  Technically, yes.

Constitutionally, in the British sense of the word, no, as a permanent arrangement.  The Prime Minister must be a member of the Commons (not the Lords).

[MASHED POTATOES. VOTE!]

The Prime Minister is answerable to the House, therefore, the Prime Minister must be a member of the House.

Right, which was the reason Douglas Home resigned his peerage to gain a seat in by-election, so he could be member of commons.

However, strictly technically, would a non-House PM allowed?

Home, IIRC, was PM for a few weeks prior to winning a by-election.  Technically, yes.

Constitutionally, in the British sense of the word, no, as a permanent arrangement.  The Prime Minister must be a member of the Commons (not the Lords).

Thanks J.J. I wasn't sure at which point Home became PM and at which exact point also a PM.

[Filuwaúrdjan]

Party leaders in the United Kingdom are chosen by their particular party caucus members.

No longer true; the Liberals stopped doing that in the 70s, Labour in 1980 and the Tories about ten years ago. Labour leaders are now chosen by an electoral college of MPs, party members and members of affiliated organisations (mostly Unions), LibDem leaders are chosen by party members, and Conservative leaders are chosen by party members from two candidates chosen by Tory MPs.

[J. J.]

I think one of those "PM's" should be "MP."  

I checked Wiki.  According to it, Home was a member of neither House for about two weeks, while PM.  http://en.wikipedia.org/wiki/Alexander_Douglas-Home

He would have been a member of the Privy Council.  The actual statutory position of the PM is the "First Lord of the Treasury."

[Linus Van Pelt]

As far as the bare parliamentary system goes, nothing prevents the Prime Minister from being in the Upper House; the Marquess of Salisbury was the last PM from the House of Lords, while in Canada John Abbott was the only Senator PM. But I think most constitutional scholars would say that by now, a convention has evolved (which in the British system can have the status of part of the Constitution) that the PM must come from the House.

[J. J.]

As far as the bare parliamentary system goes, nothing prevents the Prime Minister from being in the Upper House; the Marquess of Salisbury was the last PM from the House of Lords, while in Canada John Abbott was the only Senator PM. But I think most constitutional scholars would say that by now, a convention has evolved (which in the British system can have the status of part of the Constitution) that the PM must come from the House.

You are correct.

In the British system, the "Constitution convention" is basically an established custom.  It is flexible as in the case of Earl of Home in 1964.  The Earl:

1.  Was in the Lords (he had been an MP while a commoner).

2.  Was appointed PM.

3.  Disclaimed his peerage, but stayed as PM.

4.  Contested a bye-election.

5.  Was elected and seated in the Commons.

All in a space of about two weeks.  He was later created a life peer. 

The were consideration with Lord Curzon (who was not able to disclaim at the time) in the early 1920's, and questions about appointing Lord Halifax in 1940.

If there were any lingering questions, they where answered with Lord Hume in 1964.

[Filuwaúrdjan]

Things have changed from that point though; it would no longer be possible for anyone without a seat in the Commons to be appointed as PM.

[MASHED POTATOES. VOTE!]

Things have changed from that point though; it would no longer be possible for anyone without a seat in the Commons to be appointed as PM.

Yes, but I was talking about strictly technically possibility.

[Filuwaúrdjan]

Things have changed from that point though; it would no longer be possible for anyone without a seat in the Commons to be appointed as PM.

Yes, but I was talking about strictly technically possibility.

Ah, but it is no longer even technically possible. That's how the British Constitution works.

[J. J.]

Things have changed from that point though; it would no longer be possible for anyone without a seat in the Commons to be appointed as PM.

Yes, but I was talking about strictly technically possibility.

Ah, but it is no longer even technically possible. That's how the British Constitution works.

I'm not too sure if a short period, 2-3 weeks, would violate the constitutional convention.

[minionofmidas]

Things have changed from that point though; it would no longer be possible for anyone without a seat in the Commons to be appointed as PM.

Yes, but I was talking about strictly technically possibility.

Ah, but it is no longer even technically possible. That's how the British Constitution works.

I think Schroeder put it better than you, Al:

As far as the bare parliamentary system goes, nothing prevents the Prime Minister from being in the Upper House (...) But I think most constitutional scholars would say that by now, a convention has evolved (which in the British system can have the status of part of the Constitution) that the PM must come from the House.

[J. J.]

It is interesting to note that the delayed sitting until Home had a seat in the Commons.

[Filuwaúrdjan]

I think Schroeder put it better than you, Al

Indeed he did, indeed he did.