Sorry NSP had already been explained by several posters e.g.
link
Also a Google search throws up
from the near past
National Sectional Panel (NSP)
Where agreement is not reached locally or on cross departmental issues the NSP becomes involved. Most GMB members are represented at the Administrative Staff NSP, although our members in Engineering, IFCE and Management Grades have their own NSPs. The Administrative Staff (A Scales) NSP meets quarterly at LHR.
And from the far past
National Sectional Panel of the National Joint Council for Civil Air Transport: differences arising between British European Airways Corporation and the pilots in its employment regarding the working of certain winter schedules