The trouble with minority government is that the governments cannot even expect to rely on its own members for support, you can quite easily get a backbencher rebellion, it has happend to Labour in this current term for example, but their majority was such that these rebellions rarely had much of an effect.There have been one or two occasions where the Labour backbench rebellion was such that the Labour government had to rely on Conservative support ot pass certain crucial bills.
You get the situation where one part of the coalition does not have as effective party discpline as the other coalition partners, and this is when it tends to fall apart.
It may come as a surprise, but actually most of parliamentary business works on cross party consensus, and its only the minority of government operation that leads to adversarial votes in parliament, and it is on this basis that a minority government operates.
I think some of the reports of it being 40 years since we had a minority government are somewhat distorted, the Conservatives for at least one full term under Margaret Thatcher had to rely on the Ulster Unionists to maintain their control, because there was serious disagreement in their own ranks, they had to rely on support from other parties, they could not even control their own members. The trade off for this was that the Ulster Unionists made damn sure the price of their support was not to have any dealings in talks with Sinn Fein, and that delayed the peace process.
If we do go over to PR, then it would mean big changes to the local party political system, as the local organisations would not be able to appoint their favoured candidates, they would all come from the party central office, but then we have had list of approved candidates vetted by party HQ for years now, so it would not be impossible to work it out.
The Scots and the Welsh Nationalists would probably be more keen to work with PR and Labour since there are so few Conservative MPs in those regions, you could actually see this being that those regions have withdrawn their consent to be governed by the Conservatives in any form. This has been like it for quite a few years now, I’m pretty sure they do not want to see a Tory administration.
Conservatives have already stated quite flatly that they will not go for PR, and I don’t see how Liberal Democrat aspirations can accomodate that, unless there is some concrete commitment to a referendum on the issue.
The other point to note, given the average age of the Conservative party Association member, if they wait a few weeks, half of them will be dead anyway