Attempts to include old people in party (6)
I believe the answer is:
tories
'people in party' is the definition.
(informal term for Conservative Party members)
'attempts to include old' is the wordplay.
'attempts' becomes 'tries' ('try' can be a synonym of 'attempt').
'to include' means one lot of letters goes inside another.
'old' becomes 'o' (common abbreviation eg in OE for Old English).
'tries' placed around 'o' is 'TORIES'.
(Other definitions for tories that I've seen before include "It rose (anag)" , "Informal members of Conservative party in England" , "Old British Conservatives" , "Conservative-leaning politicians, from the Irish for 'robbers'" , "Members of the English Conservative Party" .)