The system is also used in some African, Caribbean and South Pacific countries as well as other Asian nations, including Malaysia and Nepal. New Zealand used the system until it was replaced by MMP following a nationwide referendum in 1993.
What are the advantages of FPP?
It is easy to understand. The counting of votes is likewise simple. The overall result of the election is usually clear on election night.
Under FPP, MPs are directly accountable to voters. The system favours parties with broad support, often resulting in a two-party system which, in turn, produces stable, and decisive single-party government.
A major swing of voter opinion against the governing party will usually lead to a change of Government - something not guaranteed in the multi-party parliaments spawned by proportional voting systems. While the winner-takes-all nature of FPP shuts minor parties out of parliaments, it consequently also excludes extremist ones.
What are the disadvantages of FPP?
The system pre-dates the arrival of political parties - a time when Parliament was comprised of independents representing local and regional interests.
The system was thus not ideal to cope with the evolution of political parties at a nationwide level. MPs can end up being elected to Parliament with much less than 50 per cent of the vote.
A party can win fewer votes than its main rival, yet it might win more seats and remain in government - as happened with Sir Robert Muldoon's government in 1978 and 1981. This undermines the legitimacy of such governments. The main objection to FPP, however, is that the flipside of strong government is elected dictatorship.
Without sufficient checks and balances - such as an upper house with powers to delay legislation - power is concentrated in the prime minister and a handful of senior ministers. They control the Cabinet which controls the party caucus which controls what happens in Parliament.
In New Zealand, a string of broken promises by Labour and National in the 1980s and 1990s plus the lack of a means to hold those parties to account beyond the blunt instrument of three-yearly elections led to the demise of FPP.
Another objection is voters in safe seats can feel disenfranchised if the candidate of their preferred party has no chance of winning. First-past-the-post produces huge numbers of such "wasted" votes. Moreover, the interests of all voters in safe seats can be ignored in favour of those in marginal ones which decide the outcome of elections.
Unless a party is willing to stand such candidates in its safe seats, representation of minorities suffers because of a preference for "safe" candidates in marginal seats. While FPP continues to give MMP a run for its money in opinion polls, it is unlikely the opponents of MMP will go into bat for it.
They will try to sell the supplementary member system as a suitable halfway house.