It is a plurality electoral system - the voter can only vote for one candidate the candidate with the most votes wins, winner takes all, no matter how close the vote is.
Creates: Safe seats
In 2017, Labour retained Liverpool Walton with 85% of the vote
Creates: Marginal seats
In 2017, the SNP won North East Fife by only 2 votes
Advantages:
Produces a strong, stable government - Counter arg - Theresa May's minority government in 2017, had to go into confidence and supply with the DUP
MPs have a close relationship with constituents, they meet them regularly + MPs voice their constituents concerns in Parliament
It is simple + easy to operate - very little spoilt ballots
It is quick to produce a result: (2017 Newcastle Central first to produce a result 60 mins after polls closed)
FPTP has the effect of keeping out small extremist parties (1997 The National Front ran 50 candidates, in a prop system = seats)
Disadvantages: WE VOTED AGAINST PROPORTIONAL REP 2011: AV
FPTP= two party system, government is unrepresentative
Votes are wasted on losing candidates or huge majorities, so not 'everyone's vote is 'worth the same'. (Huge majority: Tony Blair: 43.2% 418 seats)
Other systems work well: AMS produces a stable Scottish government
Most Mps do not achieve 50 per cent of the votes in their constituency= not representative (2019 Tory, 44% of vote but got 56% of seats)
It discriminates against small parties with legitimate causes + ideologies: Lib Dems= 15 seats.
Tactical voting
2017: 6.5 million voters
Example of disproportionality: Lib Dems:
In 1992 won 20% of the vote but only 20 seats (3%)