The first parliamentary test of a minority or coalition government is the vote on an amendment to the Queen’s Speech. If the Queen’s Speech is amended, the Prime Minister must resign. The Conservative party lost their majority in the December 1923 election. They put their programme to the House in January 1924 as a minority administration and lost a vote on the King’s Speech. Ramsay MacDonald was called to form a Labour administration.
More specifically the advice regarding Parliamentary elections can be found readily online:
Motion of no confidence
A government cannot operate effectively unless it can command a majority within the
House of Commons. Should it fail to enjoy the confidence of the majority of the
House, it has to hold a general election. For example, on 28 March 1979, the
Conservative Opposition defeated the Labour Government by 311-310 votes on the
motion "That this House has no confidence in Her Majesty's Government". Parliament
was dissolved on 7 April, the General Election was won by the Conservatives on 3
May, with the new Parliament summoned to meet on 9 May 1979. Governments can
also be forced into resignation or into calling a general election by being defeated in
the debate on the Queen's Speech (its legislative programme for the session) as for
instance on 21 January 1924, or losing its Finance Bill, or other major items of
legislation on which it fought a general election campaign.
As you can see, there's a little discrepancy here in the terminology, but the realities are that the 1924 "motion of no confidence" was a self-ascribed one. The motion itself said nothing about confidence in the government, but the government of the time decided to take it as such. The government lost and the Prime Minister requested to dissolve parliament.
There is, however, news that the Commons Information Office wouldn't consider this latest situation as a vote of confidence, due to the Fixed Term Parliaments Act...
BREAKING: Fixed Term Parliaments Act means amendment to Queen's Speech would NOT be a confidence vote in PM, Commons Info Office says.— Robert Hutton Squire (@RobDotHutton) May 10, 2013
Remember that this is (if true) the same body that above talks about the motions of no confidence.
There is a problem here though. There is the mixing of two different situations in to one. The first is the issue of no confidence in a Government that is leading Parliament, the second is the forcing of an election. In our past the two have been entwined, where there is a situation where a government is being hampered from doing their job as they wish to see it, the choice has been there for the prime minister to say that it has to go back to an election. Indeed the idea for the majority of Parliaments existence of a no confidence being passed against a government would mean that a party has voted against its own leader, and the need for an election after this seems obvious (though it is not the only option...)
The Fixed Term Parliaments act deals purely in the dates of elections, and not in the confidences of governments. The point of the legislation is that governments may fall, but the primary objective for Parliament is to set another government up in it's place without resorting to an election. It is, in theory, a removal of power from the Prime Minister to call elections at an opportune time, and to ensure everyone can prepare for the next election.
There is nothing stopping a government deciding that a vote on it's policies is one of confidence, indeed there is (correct me if I'm wrong) no legislation regarding motions of confidence. To read the House of Commons Standard Note on Confidence Motions this is my understanding (up to the Fixed Term Parliaments Act)
Yet, despite their central importance, there is no certainty about the rules on the form and applicability of confidence motions in the UK Parliament, as it is established by convention rather than by statute or standing order of the House.
This note goes in to detail about how a government responds to a confidence motion...
A confidence defeat for a Government will lead either to a request for a dissolution, or to the resignation of the Government. Modern practice, based on the four instances since 1895, suggests that dissolution rather than resignation is the result of a defeat. In current practice a Government is only obliged to resign or to seek a dissolution after being defeated on a confidence motion, although a significant defeat on any other motion may lead to a confidence motion
This makes me question the answer the Commons Information Office is giving on this subject. Clearly a vote against the legislative programme through an amendment is historically defined as being one of a vote of confidence (though there are issues I'll talk about below), does this mean that it is a vote to dissolve parliament? No, the two aren't necessarily entwined, even if they have been. This has always been the case though, and the Fixed Term Parliaments Act hasn't changed that.
The Fixed-term Parliaments Bill 2010-11 refers to a vote of ‘no confidence’ being passed by simple majority. It would appear that the intention is that the Government would not table a motion of no confidence in itself. However, it is not clear whether a defeat on a motion or issue of confidence would count as a vote of no confidence for the purposes of the legislation. For example, it is not clear whether a defeat on the Government’s budget would be considered as a vote of no confidence.
One possibility would be for the Government to make it clear before such a division that they considered it to be a matter of confidence; then the Speaker would certify it as such. This would effectively allow the Government to table a constructive vote of no confidence. The Speaker might rule before any debate on a motion which might be viewed as a confidence motion as to whether it would be considered as one under Clause 2(2). This might have the potential to draw the Speaker into some controversy, particularly in the case of ‘engineered’ confidence motions.
And so despite any protestations that only an explicit vote that includes the terms "That this House has no confidence in Her Majesty's Government" is the only way to perform a no confidence, legislatively it is far from as cut and dry as this. Indeed there is an entire gulf in the legislation as to what would happen if the Prime Minister chose to resign and the parliament couldn't form another government within 14 days. Would it be bound by the Fixed Term Parliaments Act to call an election, or because an explicit no confidence motion with the required words was used, could the parliament drudge on, zombie like, until the next election date?
This is especially pertinent in this scenario...for if Cameron did make it clear this was a confidence vote then he could be forced to resign this government, yet have more than 14 days to form a new one.
And this is important...despite the talk in the initial article, and the tweet above, being about a vote on the Prime Minister, it is not, only the government. Our current government is the Lib Dem/Tory coalition. A new minority Tory government would be a completely different government in the eyes of the constitution, and fully able to be led by David Cameron without issue.
This is why I don't see this issue as being one that is relevant to the ongoing Tory governance of the country, and certainly not to do with the idea of an early election...but it could very well be the start of an undermining of the coalition. If the EU referendum legislation wasn't in the Queens Speech, even if Cameron agreed on that front, to try and reinsert it (or to complain about it not being there) is essentially a snub on the Lib Dems. What it says, in practice, is that a coalition agreement between two parties can attempt to be undone by parliament, and in this case it would seem that the Prime Minister can even go along with it.
This is an executive agreeing to a legislative programme, and then part of that executive hiding behind the democratic actions of their part of the coalition to get around that agreement. If that's not a no confidence on government, I don't know what is. However if Cameron is explicit in stating that the government don't see this as an issue of confidence, constitutional practice would likely be on their side even if the amendment passed. The big thing to watch is the coalition going forward.
Confidence of the House or not, will the coalition have confidence amongst it's partners after this nefarious shifting of agreed plans?