Eden drew up plan to let Margaret marry lover Townsend

The Government made secret plans to allow Princess Margaret to marry her divorced lover, Group Captain Peter Townsend, and retain the trappings of the royal lifestyle, including the use of her title and civil list payment, documents released yesterday show.

The classified files chronicling the constitutional crisis sparked in 1955 by the relationship between the Queen's sister and the former royal equerry show that the Prime Minister, Sir Anthony Eden, was ready for the marriage to go ahead as long as Princess Margaret renounced any right to the throne for both herself and her children.

In the event, Princess Margaret, under intense public pressure and facing fierce opposition from the Church of England, announced that she would not marry the decorated wartime fighter pilot, who was 16 years her senior.

Public and media speculation that the story of forbidden love was about to end in marriage reached fever pitch shortly before the Princess's 25th birthday in August that year, after which she no longer needed to seek the monarch's approval and could have defied a refusal by the Queen to give the wedding her blessing.

When the Princess announced on 31 October that, "mindful of the church's teahing that Christian marriage is indissoluble", she had decided to put her "duty to the Queen and Commonwealth" before her love for Townsend, it was assumed that the threat of "alienation" from the Royal Family, including the loss of her HRH title and annual allowance of £15,000, had swayed her.

But documents released at the National Archives in Kew, west London, show that the Cabinet believed in the months before the announcement that Margaret was going to marry and in effect offered her a deal under which she could keep her allowance and title and continue to live in Britain and carry out her public duties as long as "public opinion" supported it.

The government also made plans to repeal the Royal Marriages Act of 1772 under which the monarch had to approve all marriages for members of the Royal Family under the age of 25.

Downing Street drew up a blueprint for the announcement of the marriage in the weeks before 31 October, including a statement from the Princess of her intention to marry Gp Capt Townsend. Marked "Draft A Top Secret", it read: "I have come to the conclusion that in all the circumstances the best course for me to follow is to marry PT and to give up my rights to the succession, both for myself and for my descendants."

A separate letter, to be sent by Sir Anthony to the prime ministers of the Commonwealth nations, made clear that the government believed Princess Margaret could not be dissuaded from her chosen course of action. It read: "It is only after long and anxious consideration that Her Royal Highness has reached this conclusion. There is no question of her changing her mind...

"Her Majesty [the Queen] would not wish to stand in the way of her sister's happiness." The letter added that, in contrast to the events which followed the abdication of her uncle, Edward VIII, to marry the divorcée Wallis Simpson, the Princess would be kept within the royal fold: "The government are advised that neither her proposed marriage nor her renunciation of her rights to the succession need in themselves affect either her style and title as 'Her Royal Highness Princess Margaret' or the provision made for her under the Civil List."

The documents, which had been subject to the 100-year rule governing papers relating to the Royal Family, were released early as part of a policy of greater transparency. But some files, notably correspondence between Downing Street and the Royal Household, have been retained.