What changes would be necessary in the UK to force a general election if the Prime Minister resigns?

Question

At present in the UK, should a prime minister be removed from office (either by resignation or made incapable of fulfilling the office due to injury, illness, or death) the party forming the government simply elects a new leader.

Of the 24 times we've had a new prime minister in the UK since 1916, twelve of these occasions happened without a general election, and only five of those went on to win a general election during their term. This leads many in the press and opposition parties to claim that the new prime minister has no mandate for many of the policies they choose to enact (an example being the manner in which Theresa May is approaching the UK's departure from the EU).

What changes would have to be made to British law to change this process? Would a simple act of parliament be sufficient?

Answer 1

What changes would have to be made to British law to change this process? Would a simple act of parliament be sufficient?

Sufficient? Yes, because there is no higher form of law in the UK (e.g. like a constitutional amendment in the US).

Necessary? Not necessarily, because much of the UK's unwritten constitution relies on custom and practice.

A particularly relevant example is the convention that the Prime Minister resigns after losing an election. There is no legal requirement to do so; and indeed, it used to be the practice that the defeated government would proceed to a Queen's speech, and only step down if the vote on that was lost (though this hasn't happened since 1924).

There is one caveat to this: under the Fixed-term Parliaments Act 2011, the PM no longer has the power to freely call an election whenever they want; they must instead either lose a confidence vote, or have the support of two-thirds of the House of Commons.

Therefore, even if a newly-appointed PM wanted to call an election, if the Opposition refused to co-operate, then it could prove impossible to do this.