Government papers: Tony Blair was urged to use ‘government machine’ to push for 1998 referendum Yes vote

As Northern Ireland's parties inched towards signing the peace deal in April 1998, declassified state papers reveal that preparations were already well advanced for planning for the referendum which would follow.

The Good Friday Agreement, also known as the Belfast Agreement, was a political deal designed to bring an end to 30 years of violent conflict in Northern Ireland.

It was signed on April 10, 1998 and approved the following month by public votes in Northern Ireland and the Republic of Ireland.

Just days earlier, on April 6, the prime minister's cabinet secretary Richard Wilson wrote a memo to Mr Blair setting out what position government ministers should take if a deal was signed and a referendum called.

He said: "My judgement is that - once ministers have decided the prior question of whether campaigning for a 'yes' vote is the best course politically - they should go on public record with a statement explaining that they will be campaigning as government ministers and, as such, will continue to draw upon the support of the government machine, including the civil service, in pursuit of their policy objectives.

"I further recommend that the scale and nature of the support given to ministers should be carefully circumscribed... to ensure the playing field is not so tilted in favour of the 'yes' campaign as to call into question the validity of the result."

Mr Wilson said there was a "respectable case for neutrality", but then pointed out ministers had campaigned for Yes votes in devolution referendums in Scotland and Wales in 1997.

He added: "Having arranged for a referendum to take place, it is incumbent upon the government to ensure that the voters understand its position on the question."

Mr Wilson then turned to the question of what support ministers should have from the "government machine", including the civil service, when campaigning for a Yes vote.

He said: "Ministers should not tilt the scales to such an extent that the validity of the result could fairly be called into question.

"At one end of the scale I would think this rules out an intensive television, radio and newspaper campaign paid for out of public funds.

"At the other end of the scale, I see absolutely no difficulty in ministers who are campaigning for the endorsement of government policy drawing upon the backing of the government machine - for example in terms of official transport during the campaign, and the production by civil servants, including government information officers, of briefing, speaking notes and material in response to questions about and criticisms of government policy.

"In providing such back-up, I think particular care will be needed to ensure that material produced is not partisan, unfair or unreasonable."

The memo said the Government should avoid "active campaigning" during the referendum campaign, leaving this instead to the Northern Ireland political parties.