DOWNING Street was engaged last night on a trawl through Government

records to establish whether there was any personal involvement of John

Major, as Prime Minister or Chancellor of the Exchequer, in the sale of

arms and defence equipment to Iraq.

Mr Paddy Ashdown has asked whether the Prime Minister was aware in

December 1990, when he assured the Liberal Democrat leader that the

guidelines on sales were being observed, that they were in fact being

breached.

This was not a matter for the judicial inquiry Mr Major announced into

the arms sales yesterday, wrote Mr Ashdown, ''it is a matter for you''.

It was ''an urgent and personal question''.

Downing Street sources said Mr Major hoped to make a substantive reply

to the letter, perhaps today.

The opposition parties' determination not to relax pressure on

Ministers because of the inquiry was strengthened by the acquisition by

Mr Robin Cook, Shadow Trade and Industry Secretary, of previously secret

Government documents about the sales.

He said they provided ''very damning evidence of the extent to which

Britain sold hundreds of millions of pounds worth of defence equipment

to Saddam Hussein within two to three years of the Gulf war.''

The documents were admitted by the Judge in the trial of three former

executives of the engineering equipment firm Matrix Churchill,

prosecuted for breaching arms sanctions against Iraq, which then

collapsed.

Mr Tam Dalyell, Labour MP for Linlithgow, speaking at Exeter

University last night, claimed the question of Mr Major's involvement

was answered by one of the documents.

A memo in June 1990 from Mr Martin Stanley, principal private

secretary to Mr Nicholas Ridley, then Trade and Industry Secretary, to

Customs made clear that their proposed action against Matrix would be

discussed by the then Prime Minister, Lady Thatcher, and her Ministers.

The letter was copied to Mr Major then Chancellor.

''Did not his conscience smite him when he was addressing British

troops during his visit to the Gulf?'' asked Mr Dalyell.

Sir David Steel, Liberal Democrat foreign affairs spokesman, wrote to

Lady Thatcher saying: ''There appears to have been a systematic

deception of Parliament and public over several years about the supply

of equipment to Iraq.''

He asked her to make clear that she would give evidence to the inquiry

to be carried out by Lord Scott and would encourage her former Ministers

to do so. ''All of these issues,'' said Sir David,'' go to the heart of

the reputation for integrity of your administration.''

Liberal Democrat defence spokesman Menzies Campbell said: ''It seems

clear that while Ministers were saying one thing in statements to the

House of Commons and in letters, they were in fact subverting the very

policy they were supposed to be pursuing.''

The problem for Ministers is whether they can convincingly claim that

while the guidelines laid down by Lord Howe, when Foreign Secretary, in

1985 may have been stretched, or in Civil Service jargon ''more

flexibly'' interpreted, they were not actually breached.

If they are successful, they can then defend themselves from the other

charge being pressed by the Opposition that Ministers who said the

guidelines were being observed, and these include both Mr Major and Lady

Thatcher, were not misleading the Commons, a resigning matter.

The Opposition is also digging to find out what went on at ministerial

meetings such as the one on July 19, 1990, chaired by the Foreign

Secretary, Mr Douglas Hurd, at which the guidelines were discussed and,

they believe, effectively altered in a more permissive direction.

Ministers have to take account of the fact that Mr Cook holds a file

of ministerial memos in which different departments display different

attitudes to the arms sales.

The Labour leader, Mr John Smith, said the public had a right to know

whether equipment was sold which could have been used against British

troops in the Gulf and whether Ministers had kept quiet about a change

of the rules on sales. ''These questions will not go away,'' he added.

He is awaiting a reply from Mr Major to a letter in which he calls for

a formal tribunal.

The Government produced court rulings which it said contradicted Mr

Cook's claim that immunity of Government papers had never been sought

before in a criminal as opposed to a civil trial.