Colin Welland made this famous prediction when picking up the Oscar for Best Original Screenplay, for his work on Chariots of Fire. He was echoing the words that are commonly attributed to the American patriot Paul Revere, who famously rode the ten miles from Concord to Lexington (both in Middlesex County, Massachusetts) on the night of 18 April 1775, to warn to the colonial militia of the approach of British forces at the beginning of the War of Independence.
According to Wikipedia, Paul Revere "did not shout the phrase" (meaning, one suspects, that he didn't say it at all). There's no doubt that Colin Welland said it, however; we've all seen the TV clip. The extent to which Welland's optimism was justified is open to debate; although Gandhi enjoyed great success the following year, and there have undoubtedly been British successes since (particularly in the acting categories), the implied 'second (or third?) British invasion' never really materialised.
© Haydn Thompson 2021