sentences:  However, when the unions who had been involved in a pay dispute for 2 years further criticised reforms at their conference, Joseph persuaded her to go ahead immediately to avoid appearing to take their side.According to Dominic Cummings, special advisor to Michael Gove, it was a catastrophic decision which led to a collapse in the integrity of the exam system.In July 1989 Thatcher called for research on the use of biological weapons against cocaine producers in Peru, in the context of the feared crack cocaine epidemic among black British people.