FOREIGN Secretary Jack Straw narrowly avoided having to resign his first job at the heart of government, newly released documents reveal today.

Mr Straw, then a young barrister, was appointed special adviser to Barbara Castle, the Secretary of State for Health and Social Security, in Harold Wilson's March 1974 government.

But he was also about to be re-elected as a member of Islington Council, posing a problem because advisers paid out of public funds were not allowed to be councillors.

The situation prompted an exchange of letters between Wilson and Castle before it was eventually decided that advisers could serve on councils at the discretion of their minister.

Following a meeting in May to consider the issue, the Prime Minister wrote to Castle: "Our attention was drawn to the case of Jack Straw, who needed to take a decision whether to allow his nomination papers to go forward for re-election to the Islington Borough Council.

"We considered this problem at some length and agreed that his nomination papers should go forward, on the understanding that, if he was elected, a choice would then have to be made: either he would have to resign as your adviser, or he would have to resign his membership of the Islington Borough Council (and of the Inner London Education Authority), or arrangements would have to be made from his remuneration as your political adviser to be paid from other than public funds."

He added that the only way Mr Straw could carry out both roles was if he was to be paid from some other source than public money.

A clearly irritated Castle replied to Wilson the next day.

"I should say that it came as a considerable shock to receive this on the very day of the election which we had authorised Jack Straw to take part in," she wrote.

"The decision conveyed in your last paragraph effectively invites me to arrange either for Jack Straw to resign from Islington Borough Council today, the day on which his election has been announced, or for him to cease to be paid.

"It is quite impracticable for me to arrange an alternative source of payment at this notice.

"Indeed I regard both the alternatives as unacceptable and at the very least I ask you to suspend your decision until I...have had a chance to discuss it with you."

Mr Straw remained an Islington councillor until 1978 and was elected to Castle's former seat in Blackburn the following year.

The documents are available to members of the public at The National Archives, Kew, south-west London, and online at the website: www. nationalarchives.gov.uk.