In 1979; only 11 seats were won by minor parties; In 2017 this only increased to 35 seats and 11% of the total seats.
In 2017; 82.4% of voters supported either Labour or Conservatives.
FPTP is a multi-party system but does not allow minor parties to succeed; due to dispersed support.
Only the 2 major parties have ever held government.
Proof that the UK has a multi-party system
Liberal Democrats in coalition government influenced AV Referendum and Gay Marriage Vote; DUP in supply-and-demand agreement with Conservatives for £1 billion funding for Northern Ireland, and a harsh Brexit deal.
English local government; in 2024 local elections, Liberal Democrats became second-largest local Party in England with 521 councillors; rise of issue-based independents such as Akmed Yakoob in West Midlands who took voters from Labour based on Gaza conflict.
Devolution; Wales saw Plaid Cymru win 12 seats in 2016; SNP dominates Scotland.