Should the First Past The Post electoral system continue to be used for Westminster elections?

Many would argue that the system of First Past The Post ("FPTP"), which is used to elect MPs in Westminster elections is flawed for a variety of reasons. Firstly, FPTP creates a system of two-party dominance. This means that often votes for third parties are wasted. This was evident in the 2015 general elections, where UKIP secured nearly four million votes, yet only won 1 seat. Conversely, the Conservatives got 11.3 million votes, and 329 seats. This highly disproportionate system is unrepresentative of the people's voice. Moreover, the unrepresentative nature of FPTP leads to a system of tactical voting, where rather than voters voting for their first preference, they settle on their second or third preference. Overall, in the long term, this could foster political disillusionment. Crucially, FPTP also creates a system of 'safe seats' where certain constituencies are de facto tied to one party, as seen in areas like Camberwell and Peckham (Labour), and Buckingham (Conservative). This not only creates voter apathy amongst those who wouldn't vote for the dominant party, it also removes the level of accountability, and scrutiny that election campaigns should bring: opposition parties won't even try to win support in these areas, the real democratic election campaigns occur in swing seats instead. Nevertheless, despite its flaws, FPTP still remains a highly effective electoral system that should continue to be used. It's one MP - one constituency link allows for a strong link between an MP and their constituents. Moreover, two-party dominance has often led to political stability in the UK; there is a clear manifesto and a clear mandate. Coalitions, which often bring political uncertainty, are rare - like that of 2010. Even more, the alternatives to FPTP are not necessarily more democratic - the London Mayoral elections use the Supplementary Vote system, which is a majoritarian system that also retains two party dominance. More proportional systems like the Closed List system, which is used in European elections, create multi-member constituencies which remove the benefit of the close MP-constituent relationship that FPTP offers. Fundamentally, there was a referendum in 2011 which gave the British people an opportunity to change the Westminster electoral system: the people voted no to change, and kept FPTP. Therefore, it is clear that FPTP should continue to be used. It has popular support - largely because it is simple to understand, therefore, there is no need to change a system that is not broken.