Becomes more communicative, suggesting Sir's not going to participate in unfair suppression (5,2)

I believe the answer is:

opens up

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'becomes more communicative' is the definition.
(I've seen this before)

I don't understand the remainder of the clue.

(Other definitions for opens up that I've seen before include "talks freely" , "Becomes more communicative" , "talks without inhibitions" , "starts shooting" .)

I've seen this clue in The Irish Times.

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