Could a British PM name the Opposition leader the next PM when they resign

Question

One of the more outlandish theories that has been doing the rounds in the British political rumour mill is:

Mr Johnson could resign and tell the Queen to send for Labour’s leader to replace him.

(source)

This sounds dramatic but is it possible?

He could resign as Conservative Party leader but this would require another Conservative MP to take the job (whether they had the confidence of the house is debatable).

But could he resign as PM? I thought to resign he needed to ensure his successor had the confidence of the house. I realise that that lying to the Queen seems de jure at the moment, but this still seems a bit much.

Wouldn't Corbyn need to be asked as well if he wanted the job?

I know the PM is doing a great job unifying the other parties, but currently, they don't agree on who would lead them if they did have to form a government. The PM should not get to tell them what to do.

Is there anything constitutionally blocking this from happening?

Answer 1

One of the more outlandish theories that has been doing the rounds in the British political rumour mill is:

Mr Johnson could resign and tell the Queen to send for Labour’s leader to replace him.

This sounds dramatic but is it possible?

A PM with no majority recommending to the Queen that the Leader of the Opposition (LotO) should be appointed as PM: in more normal times, that would be considered as routine.

Admittedly, the Labour party doesn't have a majority either; but one could assume that if the LotO becamse PM, he would try to build some kind of coalition or similar.

But could he resign as PM, I thought to resign he needed to ensure his successor has the confidence of the house.

Confidence can't be tested until after a new PM is appointed. Some other parliaments (including the Scottish Parliament) do this the other way around, by nominating the person who they want to be appointed as PM.

I realise that that lying to the queen seems de jure at the moment, but this still seems a bit much.

It could be argued that the outgoing PM has to make an educated guess. May recommended that Johnson be appointed as PM, even though she couldn't be certain that he could command a majority.

Wouldn't Corbyn need to be asked as well if he wanted the job?

It would be a courtesy, yes. (I imagine he would say yes, as the LotO is supposed to be a PM-in-waiting).

Is there anything constitutionally blocking this from happening?

In summary, I don't believe so, no.