Pushing slowly forward a kind of grunting slog (10,2)

I believe the answer is:

struggling on

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'pushing slowly forward a kind' is the definition.
I know nothing about this answer so I can't tell whether it can be defined by this definition.

'of grunting slog' is the wordplay.
'of' is an anagram indicator (the answer comes from or 'of' the letters).
'grunting'+'slog'='gruntingslog'
'gruntingslog' with letters rearranged gives 'STRUGGLING ON'.

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I've seen this clue in The Globe and Mail.

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