“level 1 of the National Curriculum levels of attainment”

1. The Education (National Curriculum) (Attainment Targets and Programmes of Study in English in respect of the Third and Fourth Key Stages) (England) Order 2008 SI
2. The Education (National Curriculum) (Attainment Targets and Programmes of Study in Mathematics in respect of the Third and Fourth Key Stages) (England) Order 2008 SI
3. The Education (National Curriculum) (Attainment Targets and Programmes of Study in Physical Education in respect of the Third and Fourth Key Stages) (England) Order 2008 SI

Definitions are taken from the instruments as published on zoomLaw, for guidance only. Check the instrument itself for its scope and any amendments.