Thatcher wanted Church to relent on Budget Day clash
Margaret Thatcher wanted the Church of England to change the enthronement of the Archbishop of Canterbury in 1980 so it did not clash with Budget Day.
Newly-released documents show the Conservatives were aware of the clash but still went for the 25 March.
The Church voiced its discontent but Mrs Thatcher wrote on a memo: "I also am very unhappy - is it possible to change the date of the enthronement?"
Bishop Runcie was enthroned on 25 March and the budget took place on 26 March.
The National Archives files show the original date of the budget was announced in the Commons on 17 January.
A day later, Colin Peterson, No 10 Secretary for Appointments, sent a memo to the PM: "Lambeth Place have told me that there is some unhappiness in the Church, apparently very much shared by the Free Churches, that Budget Day and Bishop Runcie's enthronement at Canterbury coincide on 25 March.
"People are quicker than they should be to feel that this is something of a slight by the government to Bishop Runcie."'Sheer mechanics'
End Quote Mrs Thatcher to Dr Runcie
You will know how glad I am that we have been able to change the Budget date”
The Chancellor, Sir Geoffrey Howe, wrote to Dr Robert Runcie to explain the reasoning behind the choice of date.
He assured him there was no "dark conspiracy to distract attention from the Canterbury installation".
Sir Geoffrey said the "sheer mechanics" of Budget Day made Tuesday the best day of the week, as "successive chancellors have found", and he had to choose that particular Tuesday for religious reasons.
"Ironically enough my choice has been very much influenced by the dictates of the ecclesiastical calendar," he wrote.
"With the Tuesday before Easter, and the two succeeding Tuesdays more or less ruled out, 25th March was in effect our only option."
Mrs Thatcher, who made her famous speech "The lady's not for turning" speech in 1980, clearly did a U-turn in this case and the government changed the date of the budget to Wednesday 26 March.
In a letter to Dr Runcie, who was then Bishop of St Albans, she wrote: "You will know how glad I am that we have been able to change the Budget date, and I am deeply grateful to you for the spirit in which you have spoken about this."
She wrote to the outgoing Archbishop of Canterbury, Donald Coggan, apologising for the "distress" caused. She also sent a similar letter to Cardinal Basil Hume, head of the Catholic Church in England and Wales at the time.
Dr Runcie was Archbishop of Canterbury from 1980 to 1991. His reformist tenure saw a breakdown in relations with the Tory party and he had several more run-ins with Mrs Thatcher.
His criticism of government policies on unemployment and inner cities incurred the wrath of the prime minister who accused him of failing to provide moral leadership.
And he angered her in 1982 when he asked a congregation to pray for the relatives of Argentine soldiers killed in the Falklands War.
Dr Runcie died in 2000 aged 78 after a long battle with cancer.