Advisers hoped celebrities would boost Jim Callaghan's image
An agony aunt, a football manager and a "complicated" pop star were all seen as potential allies to help Labour try to defeat Margaret Thatcher in 1979.
National Archive files show advisers wanted prime minister Jim Callaghan to appear on TV with celebrities.
"Brian Clough and Marjorie Proops are possibles. (Elton John is said to be Labour, but has a complicated image)", the briefing document says.
Labour eventually lost the election, leading to 18 years of Tory government.
The revelations are contained in a series of documents from 1979 which have been released by the National Archives.
They give an insight into the last days of the Callaghan government and the first days of Mrs Thatcher's new regime.
In the run-up to the election, Labour was far behind in the polls, so when formal campaigning began in April, the party was desperate to find anything that could boost Mr Callaghan's flagging image.
Senior policy adviser Bernard Donoughue wrote a briefing note to the prime minister, telling him "not to be disheartened by the latest polls".
Under the heading, "Style of campaign", he wrote: "Attack! Starting so far behind, we must attack, behaving like an Opposition".
Mr Donoughue - now Lord Donoughue - wanted to focus on the Tories' promise to make public sector cuts.
Labour must show either that [the Conservatives] have "no policies to achieve those objectives or where they have policies, they are bad and frightening", he said.
Mr Callaghan was advised that a "good theme" for him to talk about was: "No easy answers or simple solutions" to Britain's problems.
The note also suggested he should accuse Mrs Thatcher of lacking experience, using the argument: "Our top team is better than hers."
While celebrity campaign endorsements might be more commonly associated with the 21st century or politics across the Atlantic, Mr Donoughue thought the right "public figures" could be very useful.
He suggested that outspoken Clough, who managed Derby County, Leeds United and Nottingham Forest, and Proops - the Daily Mirror's then agony aunt - would both be suitable backers for Labour.
Wondering aloud how the party could attract young voters, he wrote: "This is always difficult (Elton John would help here)". But he added the flamboyant singer's "complicated image" should also be considered.
Jim Callaghan eventually lost to Margaret Thatcher in May 1979
Finally, Mr Donoughue noted that Mr Callaghan's best asset was something much more simple.
He wrote: "I still think your wife, children and grandchildren can win us more votes than most of the paragraphs in the manifesto.
"Mrs Thatcher does not appear to have a family."
It certainly appears that Mr Callaghan needed some encouragement, as the transcript of a conversation between him and the Maltese prime minister Dom Mintoff on 6 March 1979 - shows.
The two men talked about a possible visit by the British politician to Malta in May or June, but a melancholy Mr Callaghan said: "I might not be prime minister then.
"There comes a limit to what you can do, you know."
And he added: "We're living week to week, Dom."