Senate at first undecided on widespread government expenditure (6,8)
I believe the answer is:
public spending
'senate at first' is the definition.
I can't judge whether this definition defines the answer.
'undecided on widespread government expenditure' is the wordplay.
'undecided' becomes 'pending' (I've seen this before).
'on' means one lot of letters go next to another.
'widespread government expenditure' becomes 'publics' (I am not sure about this - if you are sure you should believe this answer much more).
'pending' put after 'publics' is 'PUBLIC SPENDING'.
Can you help me to learn more?
(Another definition for public spending that I've seen is " target for government cuts".)