Party in minutes ending in government — probable landslide? (2,7)
I believe the answer is:
no contest
'probable landslide?' is the definition.
(a landslide is a decisive electoral victory)
'party in minutes ending in government' is the wordplay.
'party' becomes 'con' (abbreviation for Conservative Party).
'in' indicates putting letters inside.
'minutes' becomes 'notes' (notes on a meeting).
'ending in' says to take the final letters.
The last letter of 'government' is 't'.
'con' inserted inside 'notes' is 'nocontes'.
'nocontes'+'t'='NO CONTEST'
(Other definitions for no contest that I've seen before include "sure-fire victory" , "one-sided fight?" , "The winner is obvious!" , "Without serious competition -- hands down" , "Outcome's already known" .)