nick clegg made the admission in a rare joint interview with his wife miriam .
lib dem said she decided against moving into ` government mansion '
` discussion 's a rather grand word for miriam basically saying no , ' he joked .
miriam claims he has put ` country above party ' at ` great personal cost '
tonight : spotlight nick clegg tonight -lrb- thursday -rrb- on itv at 7.30 pm .