If history repeats itself, first as tragedy and second as farce – according to Karl Marx – then Lord Armstrong of Ilminster is a fine oracle to consult as David Cameron prepares to announce a referendum on Britain's membership of the EU.
As principal private secretary to Harold Wilson, Armstrong had a ringside seat when the late Labour prime minister renegotiated the terms of Britain's membership of the EEC, which were put to voters in a referendum in 1975.
Armstrong, 85, believes Cameron will embark on a similar course when he pledges in the Netherlands on Friday to renegotiate a repatriation of powers which would then be put to voters in a referendum. "I think it's very alike," he says.
Students of the 1970s have been dusting off history books to see whether there are parallels between Wilson and Cameron – born 50 years apart and each with an Oxford first in PPE – who both saw a referendum as a way of dealing with party divisions over Europe.
Peter Kellner, the founder of the YouGov polling organisation, wrote this week of an "uncanny resemblance" between today and 1975, when support for pro-Europeans caught up and then overtook opponents once the issues started to be debated.
"The fear factor has begun to kick in," Kellner blogged of how the gap between supporters and opponents of the EU is closing.
Armstrong declines to be drawn on whether Cameron, who says his ultimate goal is to remain in the EU on new terms, will prevail and win a yes vote.
He puts this down to a familiar uncertainty, this time over how the EU and the eurozone will develop over the next five years.
"I don't feel at all sure of the outcome any more than I did then," he says. "Europe has come so much further since that time. I don't know how much David Cameron is thinking about Wilson.
"I don't think he wants to come out and he says he's confident that he can get what he wants and I think it's impossible to say whether he can or not.
"I think that the creation of the euro and the eurozone is a very big new factor to accommodate where I don't know what the consequences of it will be because I don't know what the outcome is going to be." Armstrong, the quintessential polished Whitehall mandarin who worked directly for four prime ministers, saw Britain's troubled relationship inside Downing Street from the moment the UK joined in 1973 until Margaret Thatcher started to turn against the EU in the late 1980s.
He was principal private secretary to Ted Heath, a close friend, who took Britain into the EEC, and was cabinet secretary when Thatcher laid the ground for today's single market in the mid-1980s.
Armstrong was one of the few people to witness one of the key moments which has parallels with today. He was at Chequers when Wilson took himself into his study for private reflection in December 1974 after the German chancellor Helmut Schmidt told the Labour party "some home truths in words of one syllable" over its plans to renegotiate its membership terms.
"For over two hours, Harold sat in the study after Schmidt had gone," Armstrong recalls. "He was entirely on his own. He made one telephone call to [foreign secretary] Jim Callaghan and then he called me in and he told me what he was going to do.
"I was obviously, having worked with Ted Heath, committed to Europe. And I can remember a sense of relief when he told me."
Wilson decided to renegotiate more modest terms and to hold a referendum. "Harold didn't get what he set out to get. But he got what he thought would be good enough to say he'd done all right." Nearly 40 years on and Cameron knows that his strategy lies in the hands of the German chancellor, Angela Merkel, who is well disposed to Britain. But, like Schmidt, who understood the need to help Britain but made clear there were limits, her patience is not finite.
As the man who will always be remembered for coining the phrase "economical with the truth", Armstrong is discreet about Cameron. But he indicates that he does not feel he is quite in the mould of some of the prime ministers he knew as he cites Sir John Major, who summoned Armstrong from retirement and who secured Britain's opt-out from the single currency at the Maastricht treaty negotiations in 1991.
"I think the stakes are very high and I think David Cameron is playing a very difficult game. It's a game rather like Mr Wilson had. I think John Major was clever enough to get the outcome that he really wanted. I'm not sure if Cameron will."
In his longest stint, Armstrong served as Thatcher's cabinet secretary from 1979-87. Like Cameron and unlike Heath, Thatcher never felt an emotional attachment to the EU though she remained wholeheartedly committed to Britain's membership, he says.
Thatcher admirers will be reassured by her response when Armstrong told her in the wake of her landslide 1983 election victory that she could be the "de facto" president of Europe. "I think I could but I don't want to be," she replied.
guardian.co.uk © Guardian News and Media Limited 2010