VOTERS in Northern Ireland are more experienced in electing politicians by proportional representation (PR) than any other part of the UK.
For almost 40 years, our councils, various Stormont assemblies, and our members of the European Parliament have all been elected by PR.
Scotland and Wales now have PR for their devolved assemblies, but they are barely a decade old. Scotland now also has it for local elections.
But Westminster elections across the UK use the same method in all 650 constituencies — the first past the post (FPTP) system.
This involves all voters giving an "X" to their preferred candidate, and whoever tops the poll in any particular constituency wins that seat, even if by one vote, and regardless of how many people voted
If there are multiple candidates, victors can win despite taking a minority of the votes.
The system works against parties such as the Liberal Democrats who tend to poll a middle amount of votes across much of the UK, meaning that they are rarely ahead in any individual constituencies.
The Conservatives and Labour, on the other hand, poll consistently well in many areas and consistently badly in other areas and so are typically guaranteed a core number of seats.
This was starkly apparent in the 1983 General Election, when Labour and the Liberals got a similar share of the vote but the former got many more seats: Labour won 27.6 per cent of the vote and got 209
seats while the Liberals (in a pact with the SDP) got 25.4 per cent and a mere 23 seats.
When the Troubles intensified in Northern Ireland in the early 1970s, the British Government was keen that no parties should be under-represented in local elections here, which would enable them to claim that the electoral system had discriminated against them, further fuelling the violence.
The first elections held under PR were the 1973 Assembly and local government elections, which used the single transferrable vote (STV) system.
This is the method that the Liberal Democrats are keen to see implemented across the UK, including for Westminster.
Typically, STV produces an outcome that most closely resembles what voters' primary preferences are.
Another alternative to FPTP is the Alternative Vote (AV) system, which is widely seen as the least "proportional".
It is hard to estimate how the main UK parties would have fared under AV if it had been the system last week.
It is easier to say what would have happened if there had been STV in
Thursday's election, because it more closely reflects overall shares of the vote.
The Tories — who got 36 per cent of the UK-wide vote — would have won around 235 seats, when under FPTP they actually got 306 (likely to rise to 307 when a last seat is decided).
Labour's 29 per cent vote share would likely have got them only 188 seats, compared to the 258 they actually won.
And the Liberal Democrats could have expected 149 seats under STV last
Thursday, when in fact they only got 57.
But these breakdowns show the problem with getting reform through the House of Commons.
Those almost 100 extra Lib Dem seats would mean up to 100 MPs from other parties losing their seats, hence the great reluctance in both the Labour and Tory parties to amend the current FPTP system.
Tory leader David Cameron had previously stopped short of promising the
immediate legislation for a referendum on voting reform offered by Gordon Brown.
He had instead offered an all-party committee of inquiry on political and electoral reform to look at possible changes.
But now Labour seems to be offering to introduce AV without a referendum.
On Monday night, in a last-ditch attempt to forge their own deal with the Liberal Democrats, the Tories offered a referendum on AV for Westminster elections.
But the Tories argue that PR would take power away from voters and result in more messy outcomes and secret backroom deals.
They say that this week's uncertainty gives a glimpse of the chaos that would follow every election.