EU federalism.

The ambitions of the UK's political elite to commit the nation to the unfettered federalism of the European Union are wrongly dated by many EU-realists to the treachery and lies of PM Edward Heath, and to a lesser extent PM Harold Wilson in 1975, when both cynically lied to the electorate - without which mendacity they could not possibly have gained their desired result in the referendum on membership.Shortly before his death - "Mr Heath, did you always know that this was to be a federal union? " - "Of course I bloody did." - {Liar Heath!}
These deceits predate this appalling pair. Any serious research into the history of the time reveals that PM Macmillan was prepared to deceive both the cabinet and the electorate as early as April 1961 as to the supranationalist intentions of the misleadingly named, Common Market.
Of course the lying by omission predates Macmillan. The full scale of the deviousness of the appalling Monnet and Spaak cannot be over emphasised. Research into this is rewarding but will make a fairminded person's knuckles go white.

Recommended. 'The Great Deception' by Chris Booker & Richard North - available 2nd hand on Amazon!