### Clue: Unionists accepting substantial Tory monetary offer, initially, but this should clear things up (4,3)
### Answer: DUST MOP 
 ### Explanation: Definition: this should clear things up
 DUP(abbrev. for the "Democratic Unionist Party", a unionist political party in N. Ireland) **containing**(accepting) **1st letters, respectively, of**(…, initially) "substantial Tory monetary offer ".
The clue makes reference to the Tory-DUP deal that enabled a minority government in the UK?