Margaret Thatcher's Secret Falklands Guilt

It's being described as "probably the single most significant historical document Margaret Thatcher ever wrote".

Now donated to a Cambridge College by her family in lieu of £900,000 inheritence tax bill, a memoir the former Prime Minister wrote about the Falklands War has been published for the first time.

The 120-page document, written over a weekend in 1983 following the conflict, details her emotions surrounding her decision to take the country to war.

When informed later that evening of the men's survival and subsequent rescue Mrs Thatcher adds "I went out walking on air. Nothing else mattered. The men were safe," the last two words underlined.

Following the successful Argentine attack on HMS Sheffield she recalls "It was difficult to get precise numbers of those who had been killed and wounded and it was an anxious time for all the relatives and for everyone in Britain.

"The rescue operation and transfer to hospital treatment on Hermes was carried out bravely"

The loss of HMS Glamorgan promoted the then Prime Minister to write "It is impossible to describe the depth of feeling at these times.

"It is quite unlike anything else I have ever experienced. In fights for liberty - we lose our bravest and best. How unjust and heartbreaking."

Equally the bombing of, and subsequent fires on, the Sir Galahad illustrates the human side of the Iron Lady "There are 'if onlys' throughout life and if only the men had been taken off and dispersed first, the casualties would never have been suffered to that extent."

On the sinking of Argentina's General Belgrano there is however little emotion in the later Baroness' account "..the submarine torpedoed the Belgrano which later sank.

"The two accompanying destroyers were not touched but were slow to pick up survivors.. We knew she had been hit but it was some hours before we knew she had sunk."

Upon finally seeing white flags flying over Port Stanley as the Argentines surrendered she intimately describes her joy "We dared not hope to much too soon.

"The House cheered, Downing Street was full of people, young people. It was their generation who had done it. Today's heroes. Britain still needs them.

"As I went to sleep very late that night I felt an enormous burden had been lifted from my shoulders.

"Future worries would be small compared with those of life or death which had been with us constantly for 11 weeks."

More from Forces TV:'We Were There: HMS Sheffield' - Survivors recall the day the ship was hit by an Argentine Exocet missile, killing 20 men.