Mr Stewart, who resigned from the Scottish Office last year after an incident in his constituency involving a pickaxe, confesses the two-year industrial dispute in the mid-1980s caused him “most heartache and trouble” and contributed to a decision to avoid further Government service. He later relented.

“The only way out for the Government was to stump up more money or concede to the Educational Institute of Scotland demands for a committee of enquiry, ” Mr Stewart recalls. “I found it very difficult personally because I had an uneasy suspicion that the teachers had a case, but the Treasury would not move a muscle.”

He was “delighted” when the dispute ended. “I was caught between having to take a strong line against the union’s action while at the same time being extremely concerned about the workload teachers had to carry. It was not only what the EIS was saying to us, but what individual teachers were telling me when I met them. I was officially in charge of handling the Government’s case and it put me through a great deal of mental anguish. I knew that the Government would not concede to the targeting of schools in Government ministers’ constituencies but at the same time children were suffering. ”

Mr Stewart acknowledges that the EIS was “very clever” in targeting ministers’ constituencies and in restricting strikes to Tuesdays, Wednesdays and Thursdays, avoiding a heavy financial burden on members. “Inevitably people were saying, why is my child’s education being destroyed because you are a Government minister? But the Government could not possibly give in to this type of pressure, otherwise where would it stop?” he writes.

Mr Stewart complains that the dispute led to long working days and to ill-health, a key factor in his decision to return to the backbenches.

In a second section in The Long March of the Market Men, the Eastwood MP praises Michael Forsyth for his tactics in filling the school boards committee in 1988 with English MPs from the right-wing No Turning Back Group who were briefed by the minister half an hour before proceedings began.

“This meant that instead of a series of critical questions which would be reported by the media we had Government backbenchers making clever interventions, such as Edward Leigh and Michael Brown, and this had to be reflected by the reporters covering the meetings,” Mr Stewart recalls.