Documents released to the Public Record Office in Kew, west London, show Churchill later boasted that the BBC had "very willingly accepted" his demand that they should not broadcast even "responsible discussion" about nuclear warfare.

The ban effectively ran for more than a decade into the mid-1960s when the BBC suppressed the infamous War Game documentary, reconstructing the effects of a nuclear attack, under Government pressure.

BBC resisted pressure

However the papers reveal that the BBC initially strongly resisted the Government's attempts to intervene, and only backed down after intense arm-twisting from ministers in Churchill's post-War administration.

Churchill intervened in 1954, at the height of Cold War paranoia about "The Bomb" after learning that the BBC was apparently planning a programme about it.

He immediately fired off a memorandum to Post Master General, the Earl De La Warr, saying that he doubted "whether it is wise that they should do this".

The governmment feared public reaction to nuclear programmes

He added: "I am sure ministers should see the script in advance, in order to satisfy themselves that it contains nothing which is contrary to the public interest".

De La Warr in turn wrote to the chairman of the BBC Board of Governors, Sir Alexander Cadogan, demanding to see in advance the script of any programme "which contains information about atomic or thermo-nuclear weapons" so the Government could issue "guidance or directions".

The point was underlined at a meeting between the minister, Cadogan and the BBC director general, Sir Ian Jacob, at which, according to the minutes, De La Warr said it would be "quite wrong" for the BBC to do anything which risked undermining public morale.

"He added that if the Prime Minister personally, speaking on behalf of the whole Government, thought a certain subject was so likely to affect international peace that it should not be the subject of uncontrolled discussion on the BBC network, surely the corporation should, as a natural course, do all it could to help the Government," the minutes noted.

Jacob said that the idea for a programme on nuclear weapons had not got beyond the initial planning stage and it would be difficult to give the assurance the Government sought, as not all programmes had scripts.

De La Warr retorted that he found it "very frightening" that somebody could go on the BBC and speak on the H-bomb without a script, let alone a programme that had not been carefully vetted.

Degree of control

The reaction of the BBC was initially defiant.

Cadogan wrote to De La Warr complaining that ministers appeared to want to exercise a degree of control "unprecedented in peace time".

"Precedents of this kind have a way of broadening with the passage of time and if extended at all widely would put the Government in the position of taking over responsibility for our output. This is a result which we doubt whether the Government would wish to see," he said.

The tone so alarmed Cabinet Secretary Sir Norman Brook, that he intervened to ensure the letter never reached Churchill.

'Do the proper thing'

Instead a second meeting was arranged, this time with the Minister of Defence Harold Macmillan present. Macmillan's approach was more emollient, but the underlying message was the same.

Nuclear topic...considered too hot to handle

He said it would be difficult for the Government to present the issues in a "well-balanced manner" if "an entirely different and possibly much more pessimistic picture were painted in the press".

He said that the "proper thing" for the BBC to do was to keep in close touch with the Ministry of Defence to ensure they did not depart from Government policy.

He added that if at any time the BBC thought of making a special programme about the effects of nuclear weapons, it would require "close consultation with his department".

This time the BBC offered no resistance.

The minutes noted: "Sir Alexander Cadogan and Sir Ian Jacob said that they would have no difficulty in falling in with the minister's suggestion".

Jacob added that it was unlikely that the BBC would want to make a programme about nuclear "fall out" but if they did "they would certainly proceed in consultation with the MoD".