The disclosure seems to have upset Mr Forsyth's political nous. What else can explain his ending the rally with David Steel's ill-judged declaration: "Go back to your constituencies and prepare for Government."
Made to a party conference in 1981, the words haunted the Liberal leader for years. Unless Mr Forsyth succeeds in defying electoral gravity on Thursday - he has a notional majority of just 236 - he will suffer similar ridicule.
The three ministers were led individually to the rostrum at George Watson's College in Edinburgh by a piper. On stage they were overshadowed by a blue-handled claymore plunged into a synthetic boulder.
This confusing piece of symbolism, Arthurian with a kilt, is one of the Scottish party's election props. The forging of the claymore was shown in a Tory election broadcast, mixing highland heritage with a bright future for Scotland through the swordsmith's high-tech children.
The ministers' theme was that Labour would "surrender" to federalism in the European Union while impoverishing Scotland through a tax-raising parliament in Edinburgh.
Mr Forsyth said he had looked into the possibility of a devolved parliament but could find no answer either to the West Lothian question or how to ensure Scotland continued to benefit from extra public spending.
Malcolm Rifkind, the Foreign Secretary, said the election would be "a referendum on Britain's future". For the first time in its history the Tory party had to appeal to unionists in all parties to join in preserving the best political union the world had ever seen. Mr Rifkind's own political future could be wrecked by a swing to Labour in Edinburgh Pentlands of 4.5 per cent.
Ian Lang, President of the Board of Trade, said a Scottish parliament would be a "rupture in the Union which could never be repaired and would lead inexorably to both the political and economic belittling of Scotland".
He said Scotland's great days were not those of "your wee bit hill and glen" with cattle getting lost in the bog, but the post-Union intellectual flowering of the Enlightenment and the Empire-building achievements of Scots explorers, missionaries and engineers.
"I don't want to see the Saltire ripped out of the flag of the Union," said Mr Lang, whose own shaky grip on Galloway and Upper Nithsdale could be dislodged by a swing to the SNP of only 2.8 per cent.Reuse content