Thanks guys - on closer reading of JSP 552, "ready for departure" is sufficient in all cases (even if a radar service is reqd on climb-out)....
I spoke to a few other pilots and my SATCO - "ready for departure and climb" certainly used to be correct, but without access to the old JSP cannot verify where it came from. Indeed SATCO thought it was still in usage :-)
Will look through the CAP in more detail, JSP 552 remains our bible though and I am sure there will be many discrepencies between the two.